JP2528923Y2 - Pneumatic actuator for brake - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic actuator for a brake such as an air-over hydraulic booster used in a vehicle or the like, and more particularly to a pneumatic actuator for a brake having a stroke detector.

[0002]

2. Description of the Related Art As a pneumatic actuator for a brake of this kind,
Conventionally, a main body forming an internal space, a movable body movably inserted into the internal space and dividing the internal space into a pressure chamber and a non-pressure chamber, and an output provided on the non-pressure chamber side of the movable body A shaft, and a switch assembly attached to a hole provided in the main body with one end positioned in the non-pressure chamber. The switch assembly includes a switch case having an inner hole, a switch main body, and a switch body. A movable member slidably fitted in an inner hole of the switch case, a spring for urging the movable member toward the one end to project from the switch case and separate from the switch body; and a switch case end portion. And a stopper member attached to the switch case as a stopper to prevent the internal parts from being removed. The stopper member is formed in advance, and the movable member is moved forward beyond a predetermined position. It is known that actuate the switch body to move the movable member, for example, Japanese Utility Model 60
In the device disclosed in Japanese Patent No. 4904, the internal parts of the switch assembly are prevented from being pulled out by caulking. Further, in the device disclosed in Japanese Patent Application Laid-Open No. 53-146079, the internal components are similarly retained by screwing a member for retaining the components into the switch case.

[0003]

[Problems to be Solved by the Invention] If the internal parts of the switch assembly are secured by caulking, equipment for caulking is necessary, and the caulking is surely prevented. Various tests must be performed to assure the quality, and many steps are required for commercialization. Further, when a failure is found in the inspection after assembling the switch assembly, there is a problem that the switch assembly has to be discarded because the internal part causing the failure cannot be replaced. . Further, in the case where the internal parts of the switch assembly are retained by screwing a retaining member, there is a problem that it takes time and effort to create a screw and to perform a screwing operation. When the switch assembly requiring many man-hours as described above is attached to the pneumatic actuator for brake, there is a problem that the man-hour for assembling the whole pneumatic actuator for brake increases.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is capable of easily assembling and disassembling, and a stroke detector capable of reliably preventing internal parts from coming off. It is an object of the present invention to provide a pneumatic actuator for a brake having a brake.

According to the present invention, there is provided a main body forming an internal space, a movable body movably inserted into the internal space and dividing the internal space into a pressure chamber and a non-pressure chamber. An output shaft provided on the non-pressure chamber side of the body, and a switch assembly attached to a hole provided in the main body with one end positioned in the non-pressure chamber. A switch body, a movable member slidably fitted in an inner hole of the switch case, and a movable member biased to the one end to protrude from the switch case and the switch body. And a stopper member attached to an end of the switch case to prevent a component inside the switch case from coming off. In a brake pneumatic actuator that moves the movable member in response to movement beyond a predetermined position to operate the switch body, the switch assembly is assembled to one of the switch case and the stopper member. When the switch case and the stopper member are elastically deformed and coupled to each other, a projection is provided for engaging the other when the stopper member is prevented from coming off.
This is achieved by a pneumatic actuator for a brake, wherein when the switch assembly is attached to a hole in the main body, the elastic deformation is restricted to maintain the connection.

[0006]

When assembling the switch assembly, the switch case and the stopper member are elastically deformed so as to pass through the protrusion while being combined, and the switch case and the stopper member are engaged via the protrusion, and the stopper member is engaged. Are locked and joined. Next, when the completed switch assembly is attached to the hole of the main body, by regulating the elastic deformation, the engagement of the switch case and the stopper member via the protrusion is prevented from being released by the elastic deformation. The connection between the switch case and the stopper member is maintained.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view of an air-over hydraulic booster as a pneumatic actuator for a brake according to an embodiment of the present invention, and FIG. 2 is an enlarged view of a main part in FIG. In the figure, the air-over hydraulic booster is indicated as a whole by 1 and comprises an air servo section 2 and a master cylinder section 3, and the figure shows a state when the air-over hydraulic booster 1 is not operated. The air servo unit 2 has a cup-shaped cylinder casing 4 and a flange member 5 which is hermetically attached to an open end of the cylinder casing 4. The master cylinder unit 3 has a through hole formed at the center of the flange member 5. And a cylinder member 6 fitted in an airtight manner. An inner space is formed by the inside of the cylinder casing 4, the left end of the flange member 5, and the left end of the cylinder member 6, and the main body 1a
Comprises a cylinder casing 4, a flange member 5 and a cylinder member 6. Cylinder casing 4
A piston 7 as a movable body and a sealing member 8 attached to the piston 7 are slidably inserted therein to divide the internal space into a left pressure chamber 9 and a right non-pressure chamber 10. . The pressure chamber 9 is connected to a brake valve or a relay valve via a connection hole 11 and a piping (not shown). The non-pressure chamber 10 is provided with an air breather device 12 above the flange member 5.
Is always in communication with the atmosphere through

A rod 13 as an output shaft is screwed to the non-pressure chamber 10 side of the piston 7. This rod 13
Is fitted into the hole 15 on the left end side of the plunger 14 with play, and the right end side of the plunger 14 extends into the cylinder hole 16 of the cylinder member 6. In the non-operating state shown in the drawing, the piston 7 and the rod 13 are urged to the left by a spring 17 to abut the inside of the cylinder casing 4, and the plunger 14 is moved to the left by a spring 19 via a retainer 18. And is in contact with the rod 13.

In the master cylinder section 3, the cylinder holes 16
Forms a stepped hole, and a sleeve 20 is fixed to the left large-diameter portion by disposing plates 21 and 22 at both ends thereof.
The sleeve 20 has an inner hole 23. Sealing members 24 and 25 are disposed between both ends of the inner hole 23 and the plates 21 and 22, and the plunger is inserted into the inner hole 23 of the sleeve 20 by the sealing members 24 and 25. 14 are fitted airtightly and liquidtightly. A sealing member 26 is mounted between the right end of the plunger 14 and the small-diameter portion of the cylinder hole 16, thereby forming a hydraulic pressure generating chamber 27. The hydraulic pressure generation chamber 27 is connected to a valve 28 provided at the right end of the plunger 14, an axial hole 29, a radial hole 30 and a through hole 31 provided in the cylinder member 6, a joint member 32 and a joint member 32. The fluid is connected to a working fluid reservoir through a piping (not shown). In the radial hole 30, a pin 33 movable in the axial direction of the plunger 14 passes through the radial hole 30, and both ends of the pin 33 have radial holes of an annular member 34 that fits with play in the plunger 14. Press-fit. The annular member 34 is urged leftward by a spring 35. The valve 28 is in contact with a wall around an opening on the right end side of the axial hole 29 and can open and close the wall.
The shaft 37 extends from the left end of the shaft 6 and penetrates the axial hole 29 so as to be movable in the axial direction. The shaft 37 is urged leftward by a spring 38. The pin 33 is in contact with the left end of the shaft portion 37 when the pin 33 is located to the right of the radial hole 30, and is apart when it is located to the left. When not shown, the annular member 34 abuts the plate 22 and the pin 3
3 is located to the right of the radial hole 30 and contacts the shaft portion 37 and pushes it to the right to open the valve 28. The hydraulic pressure generation chamber 27 is connected to a wheel cylinder of a brake device provided on a wheel via a residual pressure valve 39, a connection hole 40, and a piping (not shown) connected to the left side thereof.

Next, the stroke detector according to the present invention will be described in more detail with reference to FIG. Under the flange member 5, a through hole 41 formed with a screw on the right side
Is provided, and a switch assembly 43 pre-assembled there is screwed. The switch assembly 43 includes a switch case 4 having an inner hole 44.
5, a pipe member 46 as a movable body, a reed switch 47 and a magnet 48 as a switch body, a spring 49 for urging the pipe member 46 to the left, and a switch case 4
A stopper member 52 having a concave portion 51 formed on the left end of the switch case 45 to prevent the components inside the switch case 45 from coming off and having a convex portion 50 that can be fitted to the concave portion 51 as a protruding portion. Have.

The switch case 45 is formed of a synthetic resin such as nylon. On the left side, when the switch assembly 43 is screwed into the through hole 41, a flat surface on the left side of the through hole 41 is formed. A thin built-in portion 53 is formed to be inserted into the base. At a substantially central portion of the right switch case 45, a screw portion 5 screwed to the left female screw of the through hole 41 is provided.
A flange portion 55 is formed on the right side of the flange portion 55 so as to contact the right end of the boss portion 42 and maintain airtightness between the switch assembly 43 and the flange member 5. On the right side of the flange portion 55, a portion having a nut shape used when screwing the switch assembly 43 is provided. The inner hole 44 has a stepped shape having an opening and a large diameter portion 56 to the left, a closed bottom and a small diameter portion 57 to the right, and a step 58 between the large diameter portion 56 and the small diameter portion 57. From the bottom of the small-diameter portion 57, a small-diameter cylindrical portion 59 closed to the left extends to the left open end of the switch case 45. Inside the center hole 60 inside the tubular portion 59, lead wires 61 and 62 are connected to both terminals.
Is inserted, a reed switch 47 electrically connected to
A holding member 63 that holds the lead wires 61 and 62 is fitted to the right end of the center hole 60. This lead wire 6
1, 62 are connected to a known alarm device (not shown).

The pipe member 46 is formed of a synthetic resin, is closed only on the left end side of the pipe portion 64, and has an outward flange 65 in an opening on the right end side. A tubular portion 59 is inserted inside the pipe member 46 by narrowing a spring 49, and the pipe member 49 is incorporated movably in the axial direction with respect to the switch case 45. Also, flange 65
Has an outer diameter that can be inserted into the small diameter portion 58 of the inner hole 44. The magnet 48 has a shape surrounding the pipe 64 in an annular shape, and is formed to be movable in the axial direction of the pipe member 46. The outer portion of the right end of the magnet 48 can be brought into contact with the step 58 of the inner hole 44. When the magnet 48 comes into contact with the step 58, the reed switch 47 turns on the switch assembly 43. In such a manner as to be at the same position as the magnet 48 in the axial direction.

The stopper member 52 is formed of a synthetic resin, has an annular shape having a hole 67 into which the pipe portion 64 is inserted, and has a stepped shape having a large diameter portion 68 on the left side and a small diameter portion 69 on the right side. Is formed. A spring 66 is stretched around the small diameter portion 69 between the step portion of the large diameter portion 68 and the small diameter portion 69 of the stopper member 52 and the magnet 48, and the magnet 48 is moved rightward by the spring 66. And the inside of the right end of the magnet 48 is
Can be in contact with the flange 65. The stopper member 52 receives a biasing force to the left by the spring force of the spring 49 and the spring 66. The through hole 41 is set to be longer to the left than the position of the concave / convex joint between the switch case 45 and the stopper member 52 when the switch assembly 43 is screwed.

The spring force of the spring 49 is set to be stronger than the spring force of the spring 66. In the non-operating state shown in the drawing, the pipe member 46 is urged to the left by the spring 49, and the flange 65 is magnetized. 48 to the left, and press the magnet 48
Abuts against the right end of the stopper member 52 against the urging force of the spring 66, and the magnet 48 and the reed switch 47
Away from.

The inner diameter of the through hole 41 of the flange member 5 is φ
A, the outer diameter of the built-in portion 53 of the switch case 45 is φ
B, the outside diameter of the convex portion 50 of the stopper member 52 is φC, the inside diameter of the large diameter portion 56 of the switch case 45 is φD, the inside diameter of the hole 67 of the stopper member 52 is φE, and the outside diameter of the pipe portion 64 of the pipe member 46 is Assuming that φF, the above-described diameters are set so that the following equations are satisfied. (ΦC−φD)> (φA−φB) + (φE−φF) That is, the through hole 41 and the switch case 4 are smaller than the allowance (φC−φD) for the concave-convex coupling between the convex portion 50 and the concave portion 51.
5, the sum of the clearance (φA−φB) and the clearance (φE−φF) between the stopper member 52 and the pipe member 46 is set to be small.

Regarding the air-over hydraulic booster 1 having the configuration described above, the assembly of the switch assembly 43 will be described.

When assembling the stopper member 52 to the switch case 45, the
3 and the stopper member 52 while being elastically deformed.
The protrusion 50 is passed through the opening of the inner hole 44 until the 0 is fitted in the recess 51. When the fitting between the convex portion 50 and the concave portion 51 is completed, the elastic deformation of the built-in portion 53 and the stopper member 52 ends, and the stopper member 52 is prevented from coming off and connected to the switch case 41.

Next, when the completed switch assembly 43 is screwed and fixed to the through hole 41 of the flange portion 5, the main body 1a and the switch assembly 43 are integrated. The operation of the air-over hydraulic booster 1 assembled as described above will be described.

During operation of the brake, compressed air is supplied to the pressure chamber 9, and the piston 7 and the rod 13 move rightward due to an increase in the pressure in the pressure chamber 9. The rod 13 contacts and presses the plunger 14, and the plunger 14 also moves to the right. The plunger 14 moves while the annular member 34 is in contact with the plate 22 by the biasing force of the spring 35, and accordingly, the spring force of the spring 38 causes the pin 33 on which the shaft 37 of the valve 28 abuts. for,
The radial hole 30 moves to the right. Further plunger 14
Moves to the right, first, the valve portion 36 comes into contact with a wall around the right end side opening of the axial hole 29, the valve 28 closes, and the volume of the hydraulic pressure generating chamber 27 decreases, and the hydraulic pressure generating chamber 27 decreases. 2
The fluid pressure in 7 rises. Next, the shaft portion 37 and the pin 33
And the pin 33 contacts the left end of the radial hole 30. The hydraulic pressure in the hydraulic pressure generation chamber 27 is controlled by the residual pressure valve 39 and the connection hole 4.
The signal is transmitted to the wheel cylinder of the wheel via 0 and the brake is applied. At this time, in order to obtain the maximum braking force, even if the pressure in the pressure chamber 9 is maximized, the piston 7
Is set so as not to contact the pipe member 46 of the switch assembly 43.

When the operation of the brake is released, the pressure in the pressure chamber 9 is reduced, and the piston 7 and the plunger 14 return to the left by the spring forces of the springs 17 and 19, respectively. Hydraulic pressure generation chamber 2 due to increase in volume
The hydraulic pressure in 7 decreases, hydraulic fluid flows into the hydraulic pressure generating chamber 27 from the wheel cylinder, and the brake is loosened. At this time, the valve 28 is closed until it is pressed by the pin 33. However, if a negative pressure that overcomes the spring force of the spring 33 is generated due to the sudden decrease in the volume in the hydraulic pressure generation chamber 27, the valve is 28 opens. When the valve 28 is opened, the hydraulic fluid flows into the hydraulic pressure generation chamber 27 from the hydraulic fluid reservoir. Then, with the operation of the residual pressure valve 39, the brake is completely released.

Next, the operation of the switch assembly 43 will be described. Between the air-over hydraulic booster 1 and the wheel brake device, abnormalities such as abrasion of a friction pad of the wheel brake device beyond a predetermined position, leakage of hydraulic fluid, and breakage of the springs 17 and 19 occur. When,
The piston 7 moves to the right more than normal, and the pipe member 46 moves.
And pressed against it. As the pipe member 46 moves to the right, the magnet 48
Moves to the right until it contacts the step 58 of the inner hole 44, the reed switch 47 is activated by magnetic force, and a known alarm device (not shown) is activated to issue an alarm to the driver of the vehicle. At this time, the pipe member 46 is movable until it comes into contact with the right closed end of the small diameter portion 57 of the inner hole 44. At this time, when the piston 7 moves leftward due to a decrease in the pressure in the pressure chamber 9 or the like, the pipe member 46 is accordingly moved by the spring 4.
It moves to the left by the spring force of No. 9. When the piston 7 moves further away from the pipe member 46, the switch assembly 4
3 returns to the illustrated inoperative position.

The above-described embodiment has the following effects. In the state of the switch assembly 43 alone,
When assembling the switch assembly 43, the switch case 45 and the stopper member 52 are elastically deformed and connected to each other in an uneven manner, so that assembly can be performed easily and in a short time.
Also, when removing the stopper member 52 from the switch case 45, the switch case 4
The elastic member 5 and the stopper member 52 are elastically deformed and can be easily removed, so that the internal components of the switch assembly 43 can be easily replaced. When the switch assembly 43 is screwed into the through-hole 41 of the flange member 5, as described above, the clearance between the through-hole 41 and the switch case 45 and the stopper are smaller than the allowance for the protrusion 50 and the recess 51. The sum of the clearance between the member 52 and the pipe member 46 is set small. As a result, even if a force is applied to the stopper member 52 from the switch case 45 due to the spring force of the spring 49 and the spring 66, the elastic deformation of the stopper member 52 and the switch case 45 is restricted, and the protrusion is formed. 50
Cannot be removed from the concave portion 51 and cannot pass through the opening of the inner hole 44, so that the stopper member 52 does not come off and the internal components of the switch assembly 43 can be reliably prevented from coming off. Further, the through hole 41 is set to be longer to the left than the position of the concave / convex coupling portion between the switch case 45 and the stopper member 52 when the switch assembly 43 is screwed, so that the switch case 45 is more reliably connected. Elastic deformation is restricted.

As described above, the switch assembly 43 can be easily assembled and the number of man-hours can be reduced. Therefore, by attaching the switch assembly 43 to the main body 1a, the entire man-hour for assembling the air-over hydraulic booster 1 can be reduced. Can be reduced.

Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made based on the technical idea of the present invention. In the embodiment, the reed switch is used. However, for example, a mechanically operated switch may be used as in the above-described conventional example.

In the embodiment, the stopper member 52 is connected to the inner hole 44 of the switch case 45, but the switch case may be connected to the inside of the cup-shaped stopper member. In this case, the elastic deformation to the outside of the stopper member is restricted up to the gap between the hole of the main body and the stopper member.

In the embodiment, the switch case 45 and the stopper member 52 are elastically deformed and connected.
Only one of them may be elastically deformed, and the other may be hardly elastically deformed. In order to prevent the material from being elastically deformed, it is conceivable to change the material or make the shape highly rigid. In this way, as in the embodiment, 2
Since there is no need to regulate the clearances at the points, dimensional management is easy.

In the embodiment, the stopper member 52 is connected to the pipe member 46 of the switch case 45 through the opening, but the switch body side of the switch case, which is the opposite side, is opened. The stopper member may be connected by elastically deforming the switch case and the stopper member. Also, in this case, a screw portion is provided outside the end of the switch case on the stopper member side, and the switch assembly is screwed into the hole of the main body. The elastic deformation may be restricted. Further, at this time, the vicinity of the threaded portion of the switch case may be set to be wide outward, and the switch case may be narrowed by screwing into the hole of the main body of the switch assembly.

Further, in the embodiment, the switch case 45 and the stopper member 52 are connected by using the convex portion 50 and the concave portion 51. However, the projecting portion engages with either the switch case or the stopper member. Anything is fine. For example, a hook-shaped protrusion may be provided in the opening of the switch case toward the inside, and the stopper member inserted inside the switch case may be engaged with the hook-shaped protrusion.

Further, in the embodiment, the rigid resin is used for the switch case and the stopper member. However, any resin may be used as long as it can be elastically deformed so that the projecting portion can pass through when the switch case and the stopper member are connected. For example, similarly to the above-mentioned conventional example of Japanese Utility Model Application Laid-Open No. 60-4904, a switch case is formed by using a cylindrical metal plate, and a side where the stopper member is incorporated is caulked inward to form a protruding portion. A cut may be made in the vicinity of the protrusion in the axial direction so that the switch case is elastically deformed when assembled with the stopper member.

In the embodiment, the pipe member 46 and the stopper member 52 are separate bodies. For example, the movable member may be provided with a disc-shaped portion capable of engaging with the projecting portion. The member and the member may be formed integrally.

In the embodiment, the right end of the inner hole 44 of the switch case 45 is a closed end, and the closed end is provided with the pipe member 4.
Although the right end of 6 is abuttable, the movable member may penetrate the right end of the switch case and protrude to the outside. With this configuration, the movable member moves in the axial direction as the movable body excessively moves, so that the excessive movement of the movable body can be visually recognized. In addition, in addition to this, a concave portion is provided on one of the movable member and the switch case, and a convex portion engaging the concave portion is provided on the other, and when the movable body excessively moves, the concave portion and the convex portion are engaged. The movable member may be fixed so that the reed switch continues to operate, and when the concave-convex coupling is released, the movable member protruding outside may be manually moved. The stopper member of the present invention is effective in preventing the movable member from moving manually.

Although the air-over hydraulic booster has been described above, the present invention is not limited to this, and can be applied to other pneumatic actuators for brakes, such as a brake chamber.

[0033]

[Effects] As is clear from the above description, the present invention has the following effects. In the state of the switch assembly alone, the switch case and the stopper member are elastically deformed and engaged via the protruding portions, so that the assembly can be easily performed in a short time. Also, when the stopper member is removed from the switch case, the stopper member may be elastically deformed as described above, and the replacement of the internal parts of the switch assembly can be easily performed. When the switch assembly is mounted in the hole of the main body, the elastic deformation between the switch case and the stopper member is restricted, and the engagement between the switch case and the stopper member via the protrusion is maintained, so that the switch assembly is securely mounted. The three-dimensional internal parts can be retained.

As described above, since the switch assembly can be easily assembled and the number of man-hours can be reduced, the use of this switch assembly can reduce the number of man-hours for assembling the entire pneumatic actuator for brake.

[0035]

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an air-over hydraulic booster according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part in FIG.

[Explanation of symbols]

 4 Cylinder casing 5 Flange part 6 Cylinder member 7 Piston 9 Pressure chamber 10 Non-pressure chamber 13 Rod 14 Plunger 41 Through hole 43 Switch assembly 44 Inner hole 45 Switch case 46 Pipe member 47 Reed switch 48 Magnet 49 Spring 50 Convex part 52 Stopper Element

Claims (1)

(57) [Scope of request for utility model registration] 1. A main body forming an internal space, a movable body movably inserted into the internal space and dividing the internal space into a pressure chamber and a non-pressure chamber, and a movable body on a side of the non-pressure chamber of the movable body. An output shaft provided therein, and a switch assembly attached to a hole provided in the main body with one end positioned in the non-pressure chamber. The switch assembly includes a switch case having an inner hole and a switch main body. A movable member slidably fitted in an inner hole of the switch case, a spring for urging the movable member toward the one end to project from the switch case and separate from the switch body; and a switch. A stopper member that is attached to the end of the case as a stopper for retaining the components inside the switch case is formed and assembled in advance, and in response to movement of the movable body beyond a predetermined position. In the pneumatic actuator for brakes in which the movable member moves to operate the switch body, when the switch assembly is assembled to one of the switch case and the stopper member, the other engages with the other. Providing a projecting portion for retaining the stopper member, elastically deforming and connecting the switch case and the stopper member, and restricting the elastic deformation when the switch assembly is attached to the hole of the main body. A pneumatic actuator for a brake, wherein the coupling is maintained.