The invention refers to a helmet for motor-cyclist with inside housing for a brush folded into several parts suitable to clean from rain, mud, dust and other elements those limit the visibility. In the field of the helmets for motorbike, go-karts, quad, autos without windshield and for motor-boating sports different devices are known to clean the visor. In sporting field visors are used consist of different outside layers in transparent material. When the visibility is poor the more outside layer of the visor is pulled up and thrown away. The use of these visors is so only reserved in the sport sector such as in the traffic, throws away a layer of this visor, can determine damages or accidents to the oncoming vehicles. In the art are also known devices to clean the visor with jet of compressed air, such as the device described in the document DE202006007707U (Robert Bosch GmbH). These devices, those use compressed air for the visor cleaning, are however ineffective in the removal of parts that adhere to the visor, like mud, insects or materials off of the ground by the tires of other vehicles. For the cleaning of the visor may be used also brushes, i.e. metallic rods in partial and alternated rotation with opposite directions with profile in rubber in contact with the visor, such as the device described in the document CN201238654Y (Teng Fei). Unfortunately having a sole brush to clean the visor can be a risk such as in case of fall or accident the support rod of the brush can slip inside the helmet or to the human body causing serious physical injury to the user of the device. Further, the brush described in the stated Teng Fei patent is not suitable to effectively clean curved surfaces. Currently the helmets have aerodynamic shapes with surfaces of the visor no plane but connected with the helmet shape. For no plane visor or strongly curved is so very difficult to clean the profile of the visor with a brush fitted onto a metallic rod. It is known also the device described in patent US 6,698,032 (Robertson) wherein the clean of the curved visor is realised by rollers. The device described in the Robertson patent has, however, an use limited to helmets equipped or that can be equipped with visor and this device can be realized only on open helmets, i.e. not having the protection for the chin. The invented helmet resolves the above stated problems such as it is to be fitted on full-face helmets with curved visors. The helmet with integrated visor wiper consists of a brush to be folded inside a housing with automatic opening to allow the coming out of the brush and having a jet water pump with possibility of cleaning of the visor both with the brush than with water mixed with any detergent liquid. To reduce the brush in several parts housed, when the visor wiper is not in use, inside a housing determines a lot of advantages: improves the overall aerodynamic of the helmet, eliminates the hiss due to the action of the air onto the brush and avoids to have a sole support rod of the brush that, in case of accident, may be a danger for the helmet user such as the support rod can slip inside the same helmet. The helmet visor can, further, provide device suitable to avoid inside fogging of the visor in the raining and/or cold days. These and other advantages and aims of the invented helmet are more evident in the detailed followed description of a preferred but not limiting embodiment with reference to the annexed drawings of the sheets 1, 2, 3 and 4 those show the invented helmet in an indicative and not limiting way. In particular in sheet 1 figure 1 is electric diagram of the connections of the devices to start the brush, the water pump for the visor cleaning and to the device to prevent fogging of the inside surface of the visor. Figure 2 of the same sheet 1 is lateral view of the full-face helmet with the brush in cleaning of the visor. In sheet 2 figure 3 is upper view of the housing of the folded brush. Figure 4 of the same sheet 2 is upper view of the brush in coming out from the housing. In sheet 3 figure 5 is frontal view of a helmet with invented visor wiper not in use. The figure 6 of the same sheet 3 is frontal view with the visor wiper in use. In sheet 4 the figure 7 is perspective view of a full-face helmet with visor wiper closed inside the housing with the brush folded. The figure 8 of the same sheet 4 is perspective view of a helmet with the integrated visor wiper in use with the brush in extension and the water jet onto the visor. In a preferred but not exclusive embodiment the helmet with visor wiper comprises a brush 1 and an electric motor 2, with the brush 1 to be folded and consisting of two rods 3 and 4 for supporting the brush with plastic border 5, with the rods 3 and 4 connected between themselves by joint 6 and leaf spring 7. The leaf spring 7 consists of curved end parts 8 and 9 attached into a cavity placed in median position onto the rods 3 and 4. The brush is to be folded and placed in housing 10 kept inside said housing 10 by a restraint 1 1 consists, for example, to a solenoid-spring mechanism 12 with sliding latch 13 that goes to position itself into the cavity 14 of the rod 4 when the brush is folded and closed. Inside the housing 10 the upper end of the rod 3 is connected to a pin 15 of the electric motor 2 powered by rechargeable battery 16. This battery can be recharged with normal components from mains. The electric motor 2 can, further, to be equipped with an intermittent device 17, to be regulated in base of the needs drive of the brush for the cleaning of the visor. The rechargeable battery 16 is suitable to start also a pump 18 connected with a hydraulic circuit 19 with nozzle 20, puts in high position onto the housing 10. The hydraulic circuit 19 provides, further, a rechargeable tank 21 from which the pump 18 extracts the detergent liquid to be sprayed onto the visor. To start the pump 18 an switch 22 is provided. For coming out of the brush 1 folded in the housing 10, to start the electric motor 2 and the intermittent device 17 a switch 23 is provided, connected to the rechargeable battery 16 and to the other devices by cable 24. The housing 10 of the folded brush is placed in integrated position with the helmet so to be able to lift the visor. In using the helmet with integrated visor wiper it is provides the starting an the coming out of the folded brush closing the switch 23 by button 25 present onto the helmet. In order are so fed the restraint 11 which unhooked the folded brush 1 from the housing 10 and the electric motor 2. On the base of the data provided into the intermittent device 17 the visor is cleaning with greater of lesser frequency. In case of mud or slinging coming from the tires of other vehicles, so as other elements present onto the visor those make difficult to see, can be started by a button 26, present on the outside surface of the helmet, the hydraulic circuit 19. Pushing onto the button 26 the switch 22 is closed and the pump 18 is fed that extracts the detergent liquid to the rechargeable tank 21 and sprays it onto the visor by the nozzle 20. The folded brush 1 so cleans the helmet visor from mud, insects or other elements those adhere onto the same visor with the combo drive of the brush and the detergent liquid. When the folded brush is not in use the button 25 is pushed that open the switch 23 and off the power to the electric motor 2. The folded brush 1 is so manually placed into the housing folding the rod 4 with leaf spring 7 and placed the sliding latch 13 into the cavity 14 of the restraint 1 1. Further, the helmed can provide a device to prevent fogging in the inside surface of the visor. It is possible, infact, that when the full-face helmet is used with cold outside temperature, in raining days of with high degree of humidity, the inside part of the visor is subject of fogging. The invented helmet comprises a electric wire 27 placed inside the visor, i.e. integrated into the visor. Said electric wire 27 is connected, by conventional means to permit the contact, with electric cable 28 and in succession with a switch 29 and to the rechargeable battery 16. In using, by the button 30, the switch 29 is closed and the rechargeable battery 16 feeds the electric wire 27 that, for joule effect, warm the visor avoiding the fogging of the inside part. When the weather conditions do not need the device to prevent the fogging onto the inside surface of the visor, by the button 30, the same device is off. The invented helmet is possible of different variations and changes all part of the inventive step. All the particular are, further, to be changed with other equivalent.