LOW PRESSURE SENSOR

Technical field

The present utility model relates to a low-pressure sensor, in particular a vacuum pressure sensor having a vacuum one-way valve.

Background art

A low-pressure sensor, i.e. a sensor with an operating pressure lower than standard atmospheric pressure, is an important safety component of a hydraulic braking system of a motor vehicle, mounted between a vacuum booster and a braking vacuum source. The main function thereof is to monitor whether a sufficient degree of vacuum is stored in the vacuum booster. If there is an insufficient degree of vacuum in the vacuum booster, a monitoring signal is transmitted to a controller of the motor vehicle. Under the control of the controller, a high vacuum generated by a motor vehicle vacuum source (a petrol engine or vacuum pump) is unidirectionally accumulated in the vacuum booster, ensuring that a sufficient degree of vacuum is stored in the vacuum booster, and ensuring that the motor vehicle has sufficient vacuum servo force in various operating conditions. When a brake pedal is depressed, the vacuum booster generates boost under the action of the difference in gas pressure between the interior and the exterior, increasing the braking effect, and ensuring normal braking action, to achieve safe deceleration or braking of the motor vehicle.

A low-pressure sensor in a vehicle is generally provided with a vacuum one-way valve. The connection between the vacuum one-way valve and a body of the low-pressure sensor plays a vital role in ensuring normal, reliable operation of the low-pressure sensor. Content of the utility model

An object of the present utility model is to provide a pressure sensor with a low cost.

To this end, according to one aspect of the present application, a low-pressure sensor is provided, for monitoring the size of vacuum pressure in a vacuum booster, comprising: a sensor body, a vacuum input valve mouth and a vacuum output valve mouth, wherein the vacuum input valve mouth is a vacuum one-way valve, having one end connected to the sensor body and another end connected to a vehicle vacuum source; the vacuum output valve mouth has one end connected to the sensor body and another end connected to a vacuum booster; the sensor body comprises a first tubular part extending towards the vacuum input valve mouth; and the vacuum input valve mouth is provided with a butt-connection tube, which at least partially sheathes the first tubular part.

According to one feasible embodiment, the vacuum input valve mouth is made of a material sensitive to laser light, and the butt-connection tube is fixed in a sheathing manner outside the first tubular part by laser welding, ultrasonic welding or adhesive.

According to one feasible embodiment, a diameter of the butt-connection tube is slightly larger than a diameter of the first tubular part.

According to one feasible embodiment, a vacuum input chamber is formed in the first tubular part, and is in communication with a cavity in the vacuum input valve mouth.

According to one feasible embodiment, the vehicle vacuum source is a petrol engine or vacuum pump.

According to one feasible embodiment, the vacuum input valve mouth and the vacuum output valve mouth are disposed on different sides of the sensor body; the different sides are two adjacent sides or two opposite sides of the sensor body.

According to one feasible embodiment, the low-pressure sensor also comprises a connector, electrically connected to another system of the vehicle so as to establish communication.

According to one feasible embodiment, the connector is electrically connected to a controller of the vehicle; the controller of the vehicle is an electronic control unit of an engine.

According to one feasible embodiment, the connector is electrically connected to an Electronic Stability Program electronic control unit.

According to one feasible embodiment, the sensor body and the vacuum output valve mouth are an integrally formed element, or the sensor body and the vacuum output valve mouth are mutually independent elements, fixed together by welding/bonding.

Description of the accompanying drawings

A better understanding of the abovementioned and other features and advantages of the present utility model will be gained from the following embodiments of the present utility model, which are described with reference to the accompanying drawings. Here:

Fig. 1 shows a three-dimensional schematic diagram of a low-pressure sensor according to a preferred embodiment of the present utility model;

Fig. 2 shows a three-dimensional exploded schematic diagram of a low-pressure sensor according to a preferred embodiment of the present utility model;

Fig. 3 shows a partial sectional schematic diagram of a low-pressure sensor according to a preferred embodiment of the present utility model.

Particular embodiments

Low-pressure sensors according to preferred embodiments of the present utility model are described below with reference to the accompanying drawings.

Referring to fig. 1, a low-pressure sensor in a preferred embodiment of the present utility model is used to monitor the size of vacuum pressure in a vacuum booster, and comprises a sensor body 10, a vacuum input valve mouth 20 and a vacuum output valve mouth 30, wherein the vacuum input valve mouth 20 and the vacuum output valve mouth 30 are disposed on different sides of the sensor body 10; here, the different sides are two adjacent sides or two opposite sides of the sensor body 10. In this embodiment, the vacuum input valve mouth 20 is a vacuum one-way valve, having one end connected to the sensor body 10 and another end connected to a vehicle vacuum source (not shown); the vehicle vacuum source is for example a vehicle engine or vacuum pump. The vacuum output valve mouth 30 has one end connected to the sensor body 10 and another end connected to a vacuum booster (not shown).

Referring to figs. 2 and 3, in this embodiment, the sensor body 10 and the vacuum input valve mouth 20 are mutually independent elements, fixed together by welding/bonding. The sensor body 10 comprises a first tubular part 112 extending towards the vacuum input valve mouth 20; a vacuum input chamber 1120 is formed in the first tubular part 112, and is in communication with a cavity in the vacuum input valve mouth 20. Correspondingly, the vacuum input valve mouth 20 is provided with a butt-connection tube 200, for mating with the first tubular part 112. Preferably, the vacuum input valve mouth 20 is made of a material sensitive to laser light, and a diameter of the butt-connection tube 200 is slightly larger than a diameter of the first tubular part 112. When installation is carried out, the butt-connection tube 200 at least partially sheathes the first tubular part 112, and is fixed outside the first tubular part 112 by laser welding, ultrasonic welding or adhesive, thereby fixing the vacuum input valve mouth 20 to the sensor body 10 in a sheathing manner. Optionally, the sensor body 10 is made of a material sensitive to laser light, and a diameter of the butt-connection tube 200 is slightly smaller than a diameter of the first tubular part 112. When installation is carried out, the butt-connection tube 200 is sheathed by the first tubular part 112, and is fixed in a sheathed manner inside the first tubular part 112 by laser welding, ultrasonic welding or adhesive, thereby fixing the vacuum input valve mouth 20 to the sensor body 10.

If an embodiment is used in which the butt-connection part 200 has a slightly larger diameter than the first tubular part 112 and the butt-connection part 200 sheathes the first tubular part 112, a material sensitive to laser light must be used to make the vacuum input valve mouth 20. If an embodiment is used in which the butt-connection part 200 has a slightly smaller diameter than the first tubular part 112 and the butt-connection part 200 is sheathed by the first tubular part 112, a material sensitive to laser light must be used to make the sensor body 10. Since the vacuum input valve mouth 20 has a smaller volume than the sensor body 10, the cost of using a material sensitive to laser light to make the vacuum input valve mouth 20 is lower than the cost of using a material sensitive to laser light to make the sensor body 10; thus, by using the embodiment in which the butt-connection part 200 has a slightly larger diameter than the first tubular part 112 and the butt-connection part 200 sheathes the first tubular part 112, production costs can be lowered, so the present utility model preferably uses this embodiment. Conversely, the sensor body 10 has a larger volume than the vacuum input valve mouth 20, so a greater amount of material sensitive to laser light is needed to make the sensor body 10; this does not help to reduce costs.

Referring to fig. 3, in this embodiment, the sensor body 10 and the vacuum output valve mouth 30 may be an integrally formed element. Optionally, the sensor body 10 and the vacuum output valve mouth 30 are mutually independent elements, fixed together by welding/bonding. When it is necessary to create a vacuum, the vehicle vacuum source operates, extracting air from the interior of the vacuum output valve mouth 30, and thereby establishing a vacuum in the vacuum output valve mouth 30.

The sensor body 10 also comprises a cover 102, and is provided with an upper chamber 103; the cover 102 is mounted in a fixed manner to the sensor body 10 and covers the upper chamber 103, and a sensor chip (not shown) is provided therein. A value of negative pressure inside the vacuum booster is monitored, and a signal is transmitted to an electronic control unit of the engine.

The low-pressure sensor also comprises a connector 50, electrically connected to another system (not shown) of the vehicle so as to establish communication; the low-pressure sensor transmits a sensing signal of the size of vacuum pressure in the vacuum booster, obtained by the low-pressure sensor by monitoring, to the other system via the connector 50. For example, the connector 50 is electrically connected to a controller of the vehicle, such as the electronic control unit of the engine, for the purpose of vacuum control. Specifically, if there is an insufficient degree of vacuum in the vacuum booster, a monitoring signal is transmitted to the controller of the vehicle. Under the control of the controller, a high vacuum generated by the vehicle vacuum source (a petrol engine or vacuum pump) is unidirectionally accumulated in the vacuum booster, ensuring that a sufficient degree of vacuum is stored in the vacuum booster. The connector 50 may also be electrically connected to an Electronic Stability Program electronic control unit or another system, for a braking control strategy.

Although specific embodiments of the present utility model have already been described, these are merely presented by way of demonstration, and are not intended to limit the scope of the present utility model. On the contrary, the structure described here may be embodied in various other forms; furthermore, various substitutions and changes may be made to the structural forms described here, on condition that the spirit and scope of the present utility model are not departed from.