This invention relates to a regulating valve of the type mentioned in the preamble to claim 1.

Control valves are used quite generally for regulating pressure, flow direction and flow.

State of the art It is often necessary, both in the process industry and in various heating applications, to be able to connect two or more different fluid sources to one and the same consuming or driven unit, simultaneously or alternately. This means that it must be possible to feed two or more fluid flows (from different fluid sources) to the consuming or driven unit in question in such a manner that they can be regulated. When this is to be achieved by means of a single regulating valve, the latter must obviously be of a special type, depending on whether the different fluids (flow media) are to be supplied to the consuming/driven unit alternately only, or whether the intention is for the fluids to be supplied simultaneously in mutually adjustable proportions. Normally multi-way valves or adjustable mixing valves are then used if the choice of fluid or the proportions of the fluids to be supplied to the unit via the regulating valve is/are to be controlled by active operation of the valve from the outside.

On the other hand, when it is a question of allowing such an inherent characteristic (status value) of the fluids as their respective temperature automatically to control the fluid supply to the consuming/driven unit concerned, and what is more without any external control actuation of the valve, a quite different type of automatically operating regulating valve is required.

Objective of the invention

The objective of the invention is therefore to provide a thermomechanically regulating valve which is automatically (through the inherent regulating action of the valve) capable

of regulating the fluid supply via the valve, without external control and dependent only on the temperatures of two fluids (flow media) supplied to the valve, so that only the fluid with the higher temperature, for example, will be supplied, or if both fluids have the same temperature, so that both fluids are supplied simultaneously at the same flow rate. The above objective is achieved, and the problem solved, in that the regulating valve mentioned in the introduction exhibits the features described in the characterising part of claim 1.

A further objective is to provide a simple, reliable valve which is capable of using proven thermostats to keep down the cost of the complex regulating system.

One further objective is to provide a valve whose valve closing body simply can be controlled with two opposed thermostatic control devices so that although the two inlets are subject to a similar variation in temperature the position of the valve closing body in the valve housing is not affected, nor therefore the flow rate. The valve closing body is only rotated when the temperature variation in the inlets is similar, and the flow rate is maintained with a simple, cylindrical valve closing body.

The objectives mentioned are achieved by means of the preferred designs and refinements of the regulating valve according to the invention described in the dependent claims 2-9.

The basic problem to be solved by the invention therefore consists in causing the temperatures of the fluids supplied to the valve to be sensed and compared, by means of a thermomechanical temperature comparator designed as a regulating valve, so that the valve closing body is consequently adjusted to such-a position in the valve chamber that only the inlet for one of the fluids (e.g. the hotter fluid) to the valve chamber is kept open, whilst a second inlet for supply of the other fluid (in this case the colder fluid) is kept closed when the fluids have different temperatures. If the fluids happen to have the same temperatures the respective

inlets of the valve must be kept open, preferably to the same degree.

A regulating valve according to the invention therefore has a pair of fluid inlets on opposite sides of the valve housing, a separate temperature sensing adjusting device being installed in each inlet, which device, actuates the valve closing body via an associated motion transmitting element and shifts the valve closing body to the position in the valve chamber determined by the temperature comparison. Examples of temperature sensing adjusting devices which can be used are thermomechanical thermostats, such as wax thermostats or bimetallic thermostats.

The chamber in the valve housing containing the valve closing body should preferably have an essentially oval cross-section with a minimum diameter slightly exceeding the diameter of the preferably cylindrical valve closing body.

If the motion transmitting element of the adjusting devices is articulated to the adjusting devices a structure is obtained which is to a certain extent insensitive to intrinsically undesirable tilting of the respective adjusting devices in their surrounding inlet housing.

A certain leakage flow from the inlet to the outlet of the valve housing, which inlet is essentially closed by the valve closing body, is achieved with one particular design according to claim 5. The object of this limited, predicted leakage flow is to ensure that the adjusting device in the closed inlet is able to react relatively quickly to a temperature variation in this inlet. In the absence of such a leakage flow the adjusting device would not otherwise react to a variation in temperature of the fluid upstream from the closed inlet until the entire standing fluid volume in this inlet has assumed the new, changed temperature.

In particular, the central chamber of the valve housing (in which the valve closing body is movably arranged) may suitably

be manufactured from polymeric material such as plastic.

A special design is proposed in claim 9, in which both the housing cover sealing the chamber and the outlet housing at the opposite end of the chamber are manufactured from friction reducing material, e.g. fluoroplastic, such as Teflon. Alternatively the housing cover and the outlet housing can be manufactured from other materials, but coated with suitable friction reducing material on their inner faces adjacent to the valve closing body. These choices of materials reduce the friction between the insides of the walls of the chamber accommodating the valve closing body and the end faces of the valve closing body adjacent to or resting against them.

In its basic design the invention therefore relates to a- thermomechanical regulating valve with an inherent capacity progressively to compare the temperatures of the fluid flows through both inlets of the valve housing, and as a result of this cause the valve closing body to be adjusted, resulting in the closing of one of the inlets whilst keeping the other inlet open. Both adjusting devices of the valve are in this case connected via the motion transmitting elements (which may be angled push rods) to diametrically opposing points on the preferably cylindrical valve closing body. When the adjusting devices sense the same temperature of the fluids in both inlets, the valve closing body remains standing centrally in the valve chamber so that the fluids can flow from both inlets via the chamber to the outlet. If the fluid temperature in the first inlet should instead prove higher than that in the other inlet, the adjusting devices cause such an adjustment of the valve closing body that the second inlet is closed. This happens because the adjusting device in the first inlet causes an adjustment of the valve closing device around the point where the motion transmitting element of the second adjusting device is articulated to the valve closing body.

If, instead, the second inlet contains fluid which is hotter than the fluid in the first inlet, the regulating valve correspondingly causes the first inlet to close. If both

inlets contain fluid of the same temperature, the adjusting devices will actuate the valve closing body in equal measure from opposite directions, which causes the body to rotate about its central axis without, in so doing, being displaced into contact with the seat at the opening of one of the inlets in the valve chamber wall. As a result both inlets will then remain in open communication with the chamber and consequently with the common outlet from the same.

A thermomechanical regulating valve according to the invention may have several applications, not least for motor vehicles, such as cars and buses. For example, it can be used together with a heat accumulator or a petrol-driven heater in a vehicle, or quite generally for temperature regulation. An improved connection system should be possible, particularly for vehicles where energy is stored with a heat accumulator, using a thermomechanical regulating valve according to the invention.

The valve may be used in conjunction with such a heat accumulator system primarily for heating the vehicle interior without the water from the accumulator being cooled in the engine block. This means that the "climate" in the vehicle is given priority over an optimum reduction in exhaust emissions. Because the engine cannot be cooled by the heat exchanger circuit the heating time will be also be shortened by this connection. Where such priority is given to "climate" the engine can be heated by the engine oil with an oil heat exchanger in the heat exchanger circuit so that hot engine oil is fed directly to the engine bearings on a cold start by means of the engine oil pump. Alternatively it is conceivable, instead, to connect the valve so that the engine is heated primarily, which means that priority is given to the lowest possible exhaust emissions. The regulating valve according to the invention also provides other possibilities, since the "energy reserve" may become much larger since the heat output is lower when only the interior or only the engine is heated primarily. Since the energy reserve increases the charging time is automatically reduced. Thus the electrical circulation pump of the heat accumulator, for example, can be started with

a timer for interior heating corresponding to the heating provided by a separate petrol-driven heater. If the thermostatic regulating valve is connected to such a petrol- driven heater the entire heater output can be used for interior heating for the time it takes for the engine to reach its desired operating temperature corresponding to the temperature in the accumulator.

Brief description of the figures in the drawing The invention will now be explained in greater detail and illustrated with reference to the embodiments shown on the attached drawing.

The figures in the drawing show the following:

Fig.l and Fig.2 show, very diagrammatically, an axial section and a radial section, respectively, through a thermomechanical regulating valve according to the invention,

Fig.3 shows, in plane projection, an assembled regulating valve according to the invention,

Fig.4 shows a cross-section through the valve shown in Fig.3, along the line IV-IV, and

Fig.5 shows an axial section along the line V-V in Fig. 4.

Description of embodiments

Reference is first made to the diagrammatic design shown in Figs. 1-2. The thermomechanical regulating valve 2 shown in these figures comprises a valve housing 4, with an inner chamber 6 containing a cylindrical valve closing body 8. Valve housing 4 is provided with a first fluid inlet 10 on one side of valve housing 4, a second fluid inlet 12 on the opposite side of the valve housing, and a centrally located fluid outlet 14 at one end of chamber 6. In chamber 6, which is therefore connected to inlets 10, 12 and outlet 14, valve closing body 8 is displaceably arranged for regulating the connection between the inlets and the outlet. A temperature sensing adjusting device 16 and 18, respectively, are arranged in each inlet for comparing the temperatures of the two fluid flows fed to chamber 6 via inlets 10, 12. These adjusting devices are provided with motion transmitting elements, constructed as angled push rods 20, 22, which elements are connected at their

inner ends to valve closing body 8 by means of joints 24 and 26, which are located so that they are diametrically opposed to each other on opposite sides of a central wall 28 of valve closing body 8.

Depending on the fluid temperature sensed in inlets 10 and 12 respectively, push rods 20, 22 are displaced outwards from the respective adjusting devices as the temperature increases, enabling the position of valve closing body 8 in chamber 6 to be varied so that the body is displaced so that it comes into contact with the inside of housing 4 at the opening to either of inlets 10 and 12. In this case the inside of housing 4 forms valve seats 30, 32 in the area of the openings to inlets 10 and 12. When adjusting device 16 senses a higher fluid temperature in inlet 10 than adjusting device 18 senses in inlet 12, valve closing body 8 is consequently displaced to the right in Figs. 1-2, rotating about joint 26 until body 8 comes into contact, with its circumferential surface, with seat 32, thereby closing inlet 12. Chamber 6 in valve housing 4 has an essentially oval cross-section, as shown in Fig. 2, and the longitudinal axis of the chamber is arranged at right angles to the longitudinal directions of fluid inlets 10, 12. As shown in Fig. 1, both these longitudinal directions are parallel with each other, and as shown in Fig. 2 adjusting devices 16, 18 lie in a plane containing the centreline of valve closing body 8. To facilitate the displacement of the cylindrical valve closing body the essentially oval cross-section of the chamber can be given roughly the shape of an eight, with a waistline level with the central position of the valve closing body. For example, when adjusting device 18 is exposed to increasing temperature, push rod 22 displaces cylindrical valve body 8 so that it rotates about joint 24 causing the valve closing body to roll forward against the upper left wall of chamber 6, as shown in Figures 2 and 4, towards seat 30.

Reference is now made instead to the design of a regulating valve according to the invention shown in greater detail in Figs. 3-5. The parts of the regulating valve in Figs. 3-5 which correspond to the valve in Figs. 1-2 have been denoted by the

same reference symbols as in Figs. 1-2.

As shown particularly clear in Figs. 4 and 5, valve closing body 8 constitutes a cylindrical, hollow, tin-like body with a centrally located central wall 28. This tin-like body 8 has its opposite ends sealed by means of end covers 34, 36. Push rods 20, 22 of adjusting devices 16, 18 extend into the tin¬ like valve closing body 8 through slots 38, 40 in circumferential wall 42 of the body.

Adjusting devices 16, 18 are provided with a fastening pin 44, projecting from the rear end, which pin is securely locked in an attachment 46 inserted in the respective inlets. At their front ends adjusting devices 16, 18 are connected by a joint 48 to the respective push rods 20 and 22. As shown ^' in Fig. 4 valve housing 4 comprises a central chamber housing 50 which, on opposing sides, supports inlet housings 52 and 54, which are securely bolted to chamber housing 50. At their outer ends inlet housings 52, 54 are provided with screw-on end nipples 56, with a tubular connector 58.

Central wall 28 of valve closing body 8 forms a partition between two leakage chambers 60 and 62 inside the body, with leakage flow holes 64 and 66 respectively being located in central wall 28 and end cover 34. Leakage flow paths are formed through slots 38, 40, chambers 60, 62, holes 64 and holes 66 from the respective inlets via the inside of valve closing body 8 and out to outlet 14, which consists of an outlet housing 68 secured to one end of chamber housing 50. At the opposite end of chamber housing 50 there is a housing cover

70 securely bolted to it. Both housing cover 70 and outlet housing 68 may be suitably manufactured from a friction reducing material such as Teflon. Alternatively the housing cover and outlet housing can be manufactured from other materials which are coated with such a friction reducing material, for example a fluoroplastic. Because the inner wall surfaces of chamber 6 which are adjacent to or are in contact with end covers 34, 36 of valve closing body 8 are manufactured from or are coated with friction reducing material, the valve

closing body can be adjusted easily, and at low friction, i.e, displaced and rotated inside chamber 6 by means of the adjusting forces of adjusting devices 16, 18 transmitted via push rods 20, 22.