CN207163679U - A kind of air-tightness detection device for clutch master cylinder - Google Patents

Abstract

The utility model provides a kind of air-tightness detection device for clutch master cylinder, including main part, malleation detecting system and detection of negative pressure system.Wherein, main part includes horizontal workbench, the master cylinder detent mechanism being vertically installed in above workbench, the first detection unit and the second detection unit；Malleation detecting system is connected to oil supplying hole by the first detection unit, to provide positive air pressure for first chamber；Detection of negative pressure system is connected to oil outlet by the second detection unit, to provide negative pressure for second chamber.Air-tightness detection device of the present utility model leads to manufactures malleation and the next disposable air-tightness for detecting master cylinder different chamber and piston of subnormal ambient respectively in master cylinder different chamber, further to improve detection efficiency and accuracy rate.

Description

An air tightness detection device for a clutch master cylinder

technical field

The utility model relates to the field of vehicle production, in particular to an air tightness detection device for a clutch master cylinder.

Background technique

The clutch master cylinder is the main part of the clutch. The poor airtightness of the master cylinder will lead to many problems such as failure of the clutch during use, abnormal operation, reduced efficiency, shortened life, and environmental pollution. Therefore, the master cylinder needs to be tested for air tightness before leaving the factory. The level of air tightness testing technology will directly affect production efficiency, labor intensity of operators and final quality of products. In the prior art, air tightness is usually tested by applying a certain pressure of high-pressure gas to the test piece. However, since the clutch master cylinder is usually divided into two chambers by the piston, different chambers cannot be realized simultaneously in a single experiment. And the detection of the airtightness of the rubber plug part, while multiple detections will lead to an increase in the intensity of manual operations and a decrease in detection efficiency. Therefore, there is an urgent need for an air tightness detection device with low cost, high detection efficiency and high accuracy.

Utility model content

In order to overcome the defects in the prior art, the utility model provides an air tightness detection device for the clutch master cylinder, which can detect the master cylinder at one time by creating positive pressure and negative pressure environments in different chambers of the master cylinder. The airtightness of the different chambers of the cylinder and the piston to further improve the detection efficiency and accuracy.

The utility model relates to an air tightness detection device for a clutch master cylinder. The clutch master cylinder includes a cylinder body, an oil supply hole, an oil outlet hole, a push rod and a piston connected to one end of the push rod. Sliding inside the cylinder, the air tightness detection device includes a main body, a positive pressure detection system and a negative pressure detection system, wherein,

The main body includes a horizontal workbench, a master cylinder positioning mechanism vertically arranged above the workbench, a first detection unit and a second detection unit;

The master cylinder positioning mechanism is used to position the clutch master cylinder above the workbench, wherein the piston is positioned at the isolated and sealed position between the oil supply hole and the oil outlet hole, so that the oil supply hole and the oil outlet hole are respectively connected with the first chamber communicating with the second chamber;

The positive pressure detection system includes an inflatable device and a loop composed of an inflation port, a first standard cavity, a first detection joint, a first pressure sensor, and an air outlet through a pipeline, and the positive pressure detection system is connected to the power supply through the first detection unit. an oil hole to provide positive air pressure to the first chamber; and

Negative pressure detection system The positive pressure detection system includes an inflatable device and a loop composed of the suction port, the second standard cavity, the second detection joint, the second pressure sensor and the air inlet through the pipeline, and the negative pressure detection system passes through the second The detection unit is connected to the oil outlet to provide negative air pressure for the second chamber.

Further, the master cylinder positioning mechanism includes a base located above the workbench, a bracket perpendicular to the base, a positioning cylinder arranged directly above the bracket, and a push rod seat, a fixed support and an adjustable support arranged sequentially along the support from bottom to top ,in

A hole with a diameter smaller than the cylinder body and larger than the push rod is provided on the fixed support to support the bottom of the cylinder body;

The position of the adjustable support can be adjusted along the direction of the bracket, and the adjustable support is provided with a hole with adjustable diameter to accommodate the cylinder and limit the horizontal position of the cylinder;

The position of the push rod seat can be adjusted in the vertical direction;

The output end of the positioning cylinder is directed to the cylinder body, and the output end is provided with a lock head for locking the top position of the cylinder body, so as to cooperate with the fixed support to limit the vertical position of the cylinder body.

Further, the first detection unit includes a first column perpendicular to the workbench, a first air cylinder adjustablely fixed on the first column, and a first connecting piece fixed to the output end of the first air cylinder, and the first detection joint passes through The first connection is connected to the oil supply hole to provide positive air pressure to the first chamber.

Further, the second detection unit includes a second column perpendicular to the workbench, a second air cylinder adjustably fixed on the second column, and a second connection piece fixed at the output end of the second air cylinder, and the second detection joint passes through The second connection is connected to the oil supply hole to provide positive air pressure to the second chamber.

Further, the inflation port is connected to the inflation device through the inflation tube, and an inflation valve is arranged between the inflation port and the inflation device; the gas outlet communicates with the outside air through the outlet pipe, and the outlet pipe is provided with an outlet valve.

Further, a first pressure contrast sensor is provided between the first standard chamber and the first detection joint, a first standard chamber control valve is provided between the gas charging port and the first standard chamber, and a first standard chamber control valve is provided between the first detection joint and the gas outlet. A first master cylinder control valve is provided.

Further, the air inlet is connected to the air extraction device through an air extraction pipe, and an air extraction valve is arranged between the air extraction port and the air extraction device; the air inlet communicates with the outside air through an air inlet pipe, and an air inlet valve is arranged on the air inlet pipe.

Further, a second pressure contrast sensor is provided between the second standard chamber and the second detection joint, a second standard chamber control valve is provided between the air suction port and the second standard chamber, and a second standard chamber control valve is provided between the second detection joint and the air inlet. A second master cylinder control valve is provided between them.

A method for detecting air tightness of a clutch master cylinder, comprising the following steps:

Step 1: Fix the clutch master cylinder on the master cylinder positioning mechanism, wherein the piston of the clutch master cylinder is positioned at the isolated and sealed position between the oil supply hole and the oil outlet hole, so that the oil supply hole and the oil outlet hole are respectively connected to the first The first chamber communicates with the second chamber;

Step 2: Connect the positive pressure detection system to the oil supply hole through the first detection unit, and connect the negative pressure detection system to the oil outlet hole through the second detection unit;

Step 3: Open the inflation port and close the air outlet to inflate the first chamber for the first predetermined period of time, and use the first pressure sensor to detect whether the pressure value in the first chamber is within the first predetermined range; at the same time, open the suction port and close the air intake Pumping air for the second chamber for the first predetermined period of time, and detecting whether the pressure value in the second chamber is within the second predetermined range through the second pressure sensor;

Step 4: Open the air outlet and air inlet to restore the normal air pressure in the first front chamber and the second chamber, and the test is over.

Further, the method also includes:

Step 3' between step 3 and step 4: close the first standard chamber control valve and the first master cylinder control valve for a second predetermined period of time, and detect whether the pressure difference shown by the first pressure comparison sensor is within the third predetermined within the range; simultaneously close the second standard chamber control valve and the second master cylinder control valve for a second predetermined period of time, and detect whether the pressure difference shown by the second pressure comparison sensor is within the third predetermined range.

Due to the adoption of the above technical scheme, the utility model has the following advantages compared with the prior art:

1. The air tightness detection device of the present utility model creates positive pressure and negative pressure environments in different chambers of the main cylinder at the same time, and can complete the air tightness detection of different chambers, oil supply holes, oil outlet holes and pistons at one time, Further improve detection efficiency;

2. The air pressure difference on both sides of the piston is significantly increased, and it is easy to detect the air tightness defect of the piston, and the detection accuracy is higher;

3. The detection process is divided into the inflation/pumping detection stage and the pressure holding detection stage, which further improves the accuracy of the detection results.

Description of drawings

Fig. 1 is the schematic diagram of clutch master cylinder;

Fig. 2 is a schematic diagram of the main part of the air tightness detection device according to the present invention;

3 is a schematic diagram of a positive pressure detection system according to the air tightness monitoring device of the present invention;

Fig. 4 is a schematic diagram of a negative pressure detection system of the air tightness detection device according to the present invention.

Explanation of reference signs:

100 master cylinder, 110 cylinder block, 111 first chamber, 112 second chamber, 120 oil supply hole, 130 oil outlet hole, 140 push rod, 150 piston, 200 main body, 210 workbench, 220 master cylinder positioning mechanism , 221 base, 222 bracket, 223 push rod seat, 224 fixed support, 225 adjustable support, 226 positioning cylinder, 227 lock head, 228 connecting rod, 230 first detection unit, 231 first column, 232 first cylinder , 233 first connector, 240 second detection unit, 241 second column, 242 second cylinder, 243 second connector, 300 positive pressure detection system, 310 inflation port, 311 inflation pipe, 312 inflation valve, 320 first Standard chamber, 330 first detection joint, 340 first pressure sensor, 350 air outlet, 351 air outlet pipe, 352 air outlet valve, 360 first pressure contrast sensor, 370 first standard chamber control valve, 380 first master cylinder control valve, 400 negative pressure detection system, 410 exhaust port, 411 exhaust pipe, 412 exhaust valve, 420 second standard chamber, 430 second detection joint, 440 second pressure sensor, 450 air inlet, 451 air intake pipe, 452 air intake valve , 460 second pressure contrast sensor, 470 second standard chamber control valve, 480 second master cylinder control valve.

Detailed ways

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, not to limit the utility model.

FIG. 1 is a schematic diagram of a clutch master cylinder 100 applicable to the present invention. The master cylinder 100 has the common characteristics of a traditional master cylinder, which includes a cylinder body 110, an oil supply hole 120, an oil outlet hole 130, a push rod 140 and a piston 150 connected to one end of the push rod 140, wherein the push rod 140 can push the piston 150 Slide inside the cylinder body 110 to divide the space inside the cylinder body 110 into two different chambers, namely the first chamber 111 and the second chamber 112 . In the detection process of the present utility model, it is required to push the piston 150 to the isolation sealing position between the oil supply hole 120 and the oil outlet hole 130 by the push rod 140, even if the oil supply hole 120 and the oil outlet hole 130 are respectively connected to the first cavity The chamber 111 communicates with the second chamber 112 .

The clutch master cylinder air tightness detection device of the utility model is generally composed of a main body 200, a positive pressure detection system 300 and a negative pressure detection system 400. Figures 2-4 respectively show the specific composition of the above three parts. Wherein, the main body part 200 is used to support and locate the clutch master cylinder 100 to be tested, and will be used to provide positive air pressure for the first chamber 111 and detect its airtight positive pressure detection system 300 and for the second chamber 112 is connected to the oil supply hole 120 and the oil outlet hole 130 respectively with a negative pressure detection system 400 that provides negative air pressure and detects its airtightness.

As shown in FIG. 2 , the main body 200 includes a horizontal workbench 210 , a master cylinder positioning mechanism 220 vertically disposed above the workbench 210 , a first detection unit 230 and a second detection unit 240 . Wherein, the master cylinder positioning mechanism 220 is used to support and position the clutch master cylinder 100 to be tested, and the first detection unit 230 and the second detection unit 240 are respectively used to connect the positive pressure detection system 300 and the negative pressure detection system 400 to the power supply. Oil hole 120 and oil outlet hole 130.

The master cylinder positioning mechanism 220 includes a base 221 positioned above the workbench 210, a support 222 perpendicular to the base 221, a positioning cylinder 226 arranged directly above the support 222, and a push rod seat 223 arranged in sequence from bottom to top along the support 222, a fixed support Seat 224 and adjustable support 225. The fixed support 224 is provided with a hole with a diameter smaller than that of the cylinder body 110 and larger than that of the push rod 150 for supporting the bottom of the cylinder body 110 . The position of the adjustable support 225 can be adjusted along the direction of the bracket 222 , and the adjustable support 225 is provided with holes with adjustable diameters to accommodate cylinders 110 of different specifications and limit the horizontal position of the cylinder 110 . The position of the push rod seat 223 can be adjusted vertically so as to define the position of the push rod 140 . The output end of the positioning cylinder 226 is set toward the cylinder body 110 , and the output end is provided with a lock head for locking the top of the cylinder body 110 so as to cooperate with the fixed support 224 to define the vertical position of the cylinder body 110 . During operation, temporarily move the adjustable support 225 to a suitable position, insert the push rod of the master cylinder 100 to be tested downward into the hole of the fixed support 224, then move the adjustable support 225 down and fix it close to the cylinder. The position in the middle of the body 110, adjust the size of the hole on the adjustable support 225 to bind the cylinder 110 to prevent any horizontal displacement during the measurement process. Further adjust the position of the output end of the positioning cylinder 226 so that the lock head locks the top of the cylinder body 110, so that the cylinder body 110 is limited between the fixed support 224 and the lock head in the vertical direction to prevent it from being displaced in the vertical direction. The positioning cylinder 226 itself can be fixed on the bracket 222 or any component fixed relative to the workbench 210 . Finally, the vertical height of the push rod seat 223 is adjusted to position the piston 150 at an isolated sealing position between the oil supply hole 120 and the oil outlet hole 130 .

In an embodiment of the present utility model, the first detection unit 230 includes a first column 231 perpendicular to the workbench 210, a first cylinder 232 that is adjustable and fixed on the first column 231, and a first cylinder 232 fixed to the first cylinder. The first connector 233 of the output end of 232. During operation, the first cylinder 232 can be adjusted up and down along the first column 231 to a proper position for fixing, so that the output end of the first cylinder 232 is close to the oil supply hole 120, so as to realize the positive pressure detection system 300 and the oil supply hole 120. connect. Similarly, the second detection unit 240 includes a second column 241 perpendicular to the workbench 210 , a second air cylinder 242 adjustably fixed on the second column 241 , and a second air cylinder 242 fixed at the output end of the second air cylinder 242 . Connector 243 . Its operating principle is similar to that of the positive pressure detection unit 230 .

As shown in Figure 3, the positive pressure detection system 300 includes an inflatable device (not shown) and at least consists of an inflatable port 310, a first standard cavity 320, a first detection joint 330, a first pressure sensor 340 and an air outlet 350 through pipelines of the loop. Wherein, the inflation device is connected to the inflation port 310 through the inflation tube 311 , preferably, an inflation valve 312 for controlling the opening and closing of the inflation device may be provided between the inflation port 310 and the inflation device. The first detection joint 330 can be fixed on the first connecting piece 233 of the first detection unit 230 so as to be connected to the oil supply hole 120 of the master cylinder 100 so that the first chamber 111 becomes a part of the high-pressure gas closed circuit. The high-pressure gas provided by the inflator enters the loop through the inflatable port 310, and circulates through the standard chamber 320 and the first chamber 111. At this time, the first pressure sensor 340 can display the closed loop—that is, the first chamber 111 - the air pressure, the operator can compare the measured value with the predetermined range to find out whether the airtightness of the first chamber is good. The air outlet 350 communicates with the outside air through an air outlet pipe 351. An air outlet valve for opening and closing the air outlet 352 can be arranged on the air outlet pipe 351. After the test is finished, the air outlet valve 352 can be opened to restore the air pressure in the first chamber 111 .

Preferably, a first pressure contrast sensor 360 can be set between the first standard cavity 320 and the first detection joint 330, a first standard cavity control valve 370 can be set between the gas charging port 310 and the first standard cavity 320, and A first master cylinder control valve 380 is disposed between a detection joint 330 and the air outlet 350 . Such a design can maintain the pressure in the first standard chamber 320 and the first chamber 111 by simultaneously closing the first standard chamber control valve 370 and the first master cylinder control valve 380 after the loop is filled with high-pressure gas, once the first chamber If there is an air leak in the chamber 111 , the first pressure contrast sensor 360 will show that the high-pressure gas flows from the first standard chamber 320 to the first chamber 111 . The operator can determine whether the airtightness of the first chamber 111 is good by judging whether the pressure difference shown by the first pressure comparison sensor 360 is within a predetermined range.

FIG. 4 is a schematic diagram of a negative pressure detection system 400 . As shown in the figure, the negative pressure detection system 400 may include an air extraction device (not shown) and at least the air extraction port 410, the second standard cavity 420, the second detection joint 430, the second pressure sensor 440 and the air inlet 450 through the tube. A circle of roads. Wherein, the air extraction device is connected to the air extraction port 410 through an air extraction pipe 411 , preferably, an air extraction valve 412 for controlling the opening and closing of the air extraction device may be provided between the air extraction port 410 and the air extraction device. The second detection joint 430 can be fixed on the second connection piece 243 of the second detection unit 240 so as to be connected to the oil outlet 130 of the master cylinder 100 so that the second chamber 112 becomes a part of the negative pressure gas closed circuit. The operating principle of the negative pressure detection system 400 is similar to that of the positive pressure detection system 300 , the specific difference is that the negative pressure detection system 400 extracts the air in the closed loop through an air extraction device to create a low pressure environment for the second chamber 112 . Also preferably, a second pressure contrast sensor 460 can be set between the second standard cavity 420 and the second detection joint 430, a second standard cavity control valve 470 can be set between the gas extraction port 310 and the second standard cavity 420, and A first master cylinder control valve 480 is disposed between the second detection joint 430 and the intake port 450 . In order to determine the second chamber 112 by judging whether the pressure difference shown by the second pressure comparison sensor 460 is within a predetermined range under the condition of simultaneously closing the second standard chamber control valve 470 and the first master cylinder control valve 480 to maintain pressure Whether the airtightness is good.

Using the air tightness detection device of the present utility model to detect the air tightness of the clutch master cylinder can be implemented through the following steps:

Step 1: Fix the clutch master cylinder 100 on the master cylinder positioning mechanism 220, ensure that the piston 150 of the clutch master cylinder 100 is positioned at the isolated sealing position between the oil supply hole 120 and the oil outlet hole 130, so that the oil supply hole 120 and the oil outlet hole 130 communicate with the first chamber 111 and the second chamber 112 respectively.

Step 2: Connect the positive pressure detection system 300 to the oil supply hole 120 through the first detection unit 230 , and connect the negative pressure detection system 400 to the oil outlet hole 130 through the second detection unit 240 . Alternatively, the positive pressure detection system 300 can also be connected to the oil outlet hole 130 through the first detection unit 230, and the negative pressure detection system 400 can be connected to the oil supply hole 120 through the second detection unit 240, so that the first chamber Chamber 111 provides negative pressure and second chamber 112 provides positive pressure.

Step 3: Open the inflation port 310 and close the air outlet 350 to inflate the first chamber 111 for a first predetermined period of time, and use the first pressure sensor 340 to detect whether the pressure value in the first chamber 111 is within the first predetermined range; simultaneously open The air inlet 410 is closed and the air inlet 450 is closed to pump air into the second chamber 112 for a first predetermined period of time, and the second pressure sensor 440 is used to detect whether the pressure value in the second chamber 112 is within a second predetermined range. If the pressure value shown by the first pressure sensor 340 and/or the second pressure sensor 440 is not within the corresponding predetermined range, it indicates that the airtightness of the detected master cylinder is not good, and the detection process can be ended immediately. In the embodiment of the present utility model, the first predetermined time period and the second predetermined time period can be selected as 4s, and the first predetermined range and the second predetermined range can be based on the capacity of the detected master cylinder and the specific operation of the inflator and the air extraction device parameters to be determined.

When the detection device includes a pressure comparison sensor, the pressure holding and pressure comparison test can be performed after the above detection is completed, specifically step 3': closing the first standard chamber control valve 370 and the first master cylinder control valve 380 for a second predetermined time Section, detect whether the pressure difference shown by the first pressure contrast sensor 360 is within the third predetermined range; simultaneously close the second standard cavity control valve 470 and the second master cylinder control valve 480 for a second predetermined period of time, and detect the second pressure Compare whether the pressure difference shown by the sensor 460 is within the third predetermined range. If the pressure values shown by the first pressure comparison sensor 360 and/or the second pressure comparison sensor 460 are not within the corresponding predetermined range, it indicates that the airtightness of the detected master cylinder is poor, and the detection process can be ended immediately. In the embodiment of the present invention, the third predetermined time period and the fourth predetermined time period can be selected as 2s, and the third predetermined range and the fourth predetermined range can be determined according to specific test conditions.

Step 4: Open the air outlet and air inlet to restore the normal air pressure in the first front chamber and the second chamber, and the test is over.

The air tightness detection device of the utility model simultaneously detects the two chambers of the main cylinder by using two groups of detection systems, thereby effectively improving the operation efficiency. The two groups of detection systems adopt positive pressure and negative pressure respectively, which can detect the airtightness of the piston more accurately than both chambers adopting positive pressure/negative pressure, so that the detection result is more accurate.

The above examples only express the implementation manner of the utility model, and the description thereof is relatively specific and detailed, but it should not be understood as limiting the patent scope of the utility model. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the utility model, and these all belong to the protection scope of the utility model. Therefore, the scope of protection of the utility model patent should be based on the appended claims.

Claims (8)

1. a kind of air-tightness detection device for clutch master cylinder, the clutch master cylinder includes cylinder body, oil supplying hole, fuel-displaced Hole, push rod and the piston for being connected to described push rod one end, the push rod promote the piston to be slided in the cylinder interior, its It is characterised by, the air-tightness detection device includes main part, malleation detecting system and detection of negative pressure system, wherein,

The main part includes horizontal workbench, the master cylinder detent mechanism being vertically installed in above the workbench, first Detection unit and the second detection unit；

The master cylinder detent mechanism is used to the clutch master cylinder being positioned above the workbench, wherein the piston is determined Isolating seal position between the oil supplying hole and the oil outlet so that the oil supplying hole and the oil outlet respectively with First chamber connects with second chamber；

The malleation detecting system includes aerating device and by inflation inlet, the first standard chamber, the first detection tabs, first pressure The loop that sensor and gas outlet are made up of pipeline, and the malleation detecting system is connected by first detection unit To the oil supplying hole, to provide positive air pressure for the first chamber；And

Malleation detecting system described in the detection of negative pressure system includes aerating device and by bleeding point, the second standard chamber, second The loop that detection tabs, second pressure sensor and air inlet are made up of pipeline, and the detection of negative pressure system passes through institute State the second detection unit and be connected to the oil outlet, to provide negative pressure for the second chamber.

2. the air-tightness detection device according to claim 1 for clutch master cylinder, it is characterised in that the master cylinder is determined Position mechanism includes the base above the workbench, the support perpendicular to the base, is arranged at directly over the support Positioning cylinder and the ram seat, hold-down support and the adjustable seats that are set gradually from bottom to up along the support, wherein

Diameter is provided with the hold-down support less than the cylinder body and more than the hole of the push rod, to support the bottom of the cylinder body Portion；

The position of the adjustable seats can be adjusted along the direction of the support, and be provided with diameter in the adjustable seats Adjustable hole, to accommodate the cylinder body and to limit the horizontal level of the cylinder body；

The position of the ram seat can vertically be adjusted；

The output end of the positioning cylinder is set towards the cylinder body, is provided with the output end for locking the cylinder body top The tapered end of portion position, to coordinate the hold-down support to limit the upright position of the cylinder body.

3. the air-tightness detection device according to claim 1 for clutch master cylinder, it is characterised in that first inspection Survey unit include perpendicular to the workbench the first column, be adjustably fixed on first column the first cylinder, And the first connector of the output end of first cylinder is fixed on, first detection tabs pass through first connector The oil supplying hole is connected to, to provide positive air pressure for the first chamber.

4. the air-tightness detection device according to claim 1 for clutch master cylinder, it is characterised in that second inspection Survey unit include perpendicular to the workbench the second column, be adjustably fixed on second column the second cylinder, And the second connector of the output end of second cylinder is fixed on, second detection tabs pass through second connector The oil supplying hole is connected to, to provide positive air pressure for the second chamber.

5. the air-tightness detection device according to claim 1 for clutch master cylinder, it is characterised in that the inflation inlet The aerating device is connected to by gas tube, charging valve is provided between the inflation inlet and the aerating device；It is described Gas outlet is connected by escape pipe with outside air, and outlet valve is provided with the escape pipe.

6. the air-tightness detection device according to claim 1 for clutch master cylinder, it is characterised in that first mark First pressure contrast sensor, the inflation inlet and the first standard chamber are provided between quasi- chamber and first detection tabs Between be provided with the first standard chamber control valve, and be provided with the first master cylinder between first detection tabs and the gas outlet Control valve.

7. the air-tightness detection device according to claim 1 for clutch master cylinder, it is characterised in that the bleeding point Air extractor is connected to by exhaust tube, evacuating valve is provided between the bleeding point and the air extractor；The air inlet Mouth is connected by air inlet pipe with outside air, and air intake valve is provided with the air inlet pipe.

8. the air-tightness detection device according to claim 1 for clutch master cylinder, it is characterised in that second mark Second pressure contrast sensor, the bleeding point and the second standard chamber are provided between quasi- chamber and second detection tabs Between be provided with the second standard chamber control valve, and be provided with the second master cylinder between second detection tabs and the air inlet Control valve.