JPH0519682U - Brake device - Google Patents

Abstract

(57) [Summary] [Purpose] To consolidate the service brake and auxiliary brake in one place and eliminate mechanical links for simplification. [Structure] When the foot pedal is depressed, a fluid is supplied to a first hydraulic chamber 30, and the hydraulic pressure causes a piston 24 to abut against a brake disk 23 to brake the rotary disk 22. On the other hand, at the time of parking or the like, the force against the compression spring 47 to the pressing body 36 is removed by stopping the supply of the pressure oil to the second hydraulic chamber 38, and the pressing body 36 is pressed against the piston 24 by the compression spring 47. The urging force presses the brake disc 23 onto the rotating disc 22.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a brake device used in a cargo handling vehicle such as a wheel loader, and more particularly to the arrangement of a service brake, a parking brake, and an emergency brake.

[0002]

[Prior Art]

 Generally, as a brake device for a cargo handling vehicle such as a wheel loader, a service brake SB that is driven when an operator steps on a foot brake during normal vehicle operation, a parking brake PB that is driven during parking, and a vehicle. Emergency brakes EB are provided for driving in an emergency during operation. The conventional example is shown below.

(1) FIG. 3 shows an attachment position in a cargo handling vehicle in an example of a conventional braking device (conventional example 1). The brake device of this example is a dry multi-plate type, and the service brake SB is directly attached to each wheel. On the other hand, the parking brake PB or the emmergence brake EB is arranged at the end of the counter shaft 2 of the transmission 1.

Here, FIG. 4 is a cross-sectional view of essential parts showing the parking brake PB or the emmergence brake EB of Conventional Example 1. In FIG. 4, 3 is a rotating disk fixed to the counter shaft 2, 4 is a brake disk that abuts the rotating disk 3 to stop the rotation of the counter shaft 2 during braking, and 5 is the rotating disk 3 side ( Hereinafter, a plate for pushing in the braking direction X1), 6 a piston for pushing the plate 5 in the braking direction X1 during braking, 7 a spring for pushing the piston 6 in the braking direction X1, 8 for no braking (hereinafter, non-braking) A fluid pressure chamber for holding the piston 6 against the spring 7 in the direction opposite to the braking direction X1 (hereinafter, referred to as X2 direction) at time 10), and 9 is a seal.

Then, normally, the pressure oil is guided to the fluid pressure chamber 8. Therefore, since the spring 7 is compressed, both the disks 3 and 4 are released from each other, and the brake is not applied.

However, when the brake is applied by the intention of the operator, the pressure oil to the fluid pressure chamber 8 is cut by operating the lever or the button. When the fluid pressure in the fluid pressure chamber 8 is exhausted, both discs 3 and 4 are brought into contact with each other by the force of the spring 7, and the brake can be activated.

(2) An example of a conventional wet multi-plate brake device is shown in FIGS. 5 and 6 (conventional example 2). FIG. 5 is a diagram showing a mounting position of a brake device of Conventional Example 2 in a vehicle, and FIG. 6 is a sectional view of the same.

As shown in FIG. 5, the brake device of the present embodiment is a combined type of a service brake unit and a parking brake unit, which is mechanically operated to brake the output shaft shift L1 of the transmission 1. As described above, the lever 10 is connected to the control cable, and the ball cam 11 between the piston 6 and the housing 8a, which is connected to the lever 10 according to the pulling condition of the lever 10, moves on the slope of the groove of the piston 6 to move the piston. 6 presses disk 3 against disk 4 and brakes output shutter L1. Here, the service brake SB, the parking brake PB, or the emergency brake EB are all mechanical braking by the lever 10. Therefore, according to this example, there is a merit that the essential mechanism of each brake SB, PB, EB can be unified as compared with the conventional example 1.

[0009]

[Problems to be solved by the device]

 (1) The parking brake PB and the emergency brake EB of the conventional example 1 shown in FIG. 4 cannot be used for the service brake SB due to their capacity, and therefore a two-system braking mechanism was present. Therefore, the number of parts was large and the cost was high.

(2) Further, in the conventional example 2 shown in FIGS. 5 and 6, the following drawbacks are pointed out.

[A] The service brake SB drives the lever 10 via a fluid pressure and a mechanical link (not shown), while the parking brake PB and the emergent brake EB are mechanical links and cables (not shown). The lever 10 is driven via (). For this reason, as in the case of Conventional Example 1, the operating system eventually becomes two systems, and the mechanism such as the mechanical link and cable of the parking brake PB and the emmergence brake EB is complicated, and the number of parts increases. The cost was high and the failure rate was high.

[B] In a long-running vehicle, a brake time lag occurs due to wear of the ball cam 11 and link pin of a mechanical link, extension of a cable, and the like, which slows the operation of the brake, and this It took a lot of time to adjust.

[C] When the brake is overhauled, the braking device is attached to the output shaft L 1 in a skewered manner. Therefore, the braking device must be repaired after removing the output shaft from the vehicle body. It was troublesome to attach and detach it.

In view of the above, it is an object of the present invention to provide a brake device that can reduce the number of parts by consolidating the mechanical structure of each brake.

[0015]

[Means for Solving the Problems]

 As shown in FIGS. 1 and 2, a means for solving the problems according to the first aspect of the present invention is to rotate a rotary disk 22 mounted on a rotary shaft 26 in a housing 21 and to stop the rotation of the rotary shaft 26 by contacting the rotary disk 22. The brake disc 23, a service brake unit SBX that presses the both discs 22, 23 when an operator steps on the foot brake, and an auxiliary brake unit PBX that presses the both discs 22, 23 during parking or in an emergency. The service brake unit SBX includes a piston 24 that causes the brake disk 23 to come into contact with and separate from the rotary disk 22 along a rotary shaft 26, and a first piston that is disposed on the opposite side of the braking direction X1 of the piston 24 during braking. And a first fluid supply source 31 for supplying fluid to the fluid pressure chamber 30, wherein the auxiliary brake unit PBX is Stone 24, a pressing body 36 that abuts against the back surface of the piston 24 to press it, an urging means 37 that urges the pressing body 36 in a direction of abutting the piston 24, and the pressing body when the brake is not operating. A second fluid pressure chamber 38 formed between the front surface of the piston 36 on the piston 24 side and the housing 21 is supplied with a second fluid pressure chamber 38 to separate the pressing body 36 from the piston 24 against the biasing means 37. And a fluid supply source 39.

According to a second aspect of the present invention, the rotary disk 22 according to the first aspect is fixed to the end of the counter shaft 26 of the transmission, and the service brake unit SBX and the auxiliary brake according to the first aspect. The part PBX is arranged adjacent to the end of the counter shaft 26.

According to a third aspect of the present invention, the biasing means 37 according to the first aspect comprises a plurality of compression springs, and the housing 21 according to the first aspect prevents the compression spring from falling. A positioning plate 48 for positioning between the housing 21 and the pressing body 36 is fixed.

According to a fourth aspect of the present invention, in the brake device according to the first aspect, the rotation preventing means 42 for preventing the rotation of the pressing body 36 is provided, and the rotation preventing means 42 is the pressing body. 36, a fitting hole 44 formed in parallel with the direction of the rotating shaft 26, and a restriction pin 43 fixed to the housing 21 and fitted into the fitting hole 44 to restrict the rotation of the pressing body 36. Is.

[0019]

[Action]

 In the problem solving means according to claim 1, when the vehicle is not braked, the second fluid supply source 39 supplies the fluid to the second fluid pressure chamber 38, and the pressing body 36 is urged in the opposite direction to the braking direction X1. Then, the pressing body 36 is separated from the piston 24. Then, the rotary disk 22 and the brake disk 23 are not in contact with each other, and the brake is in an unprecedented state.

Here, when the operator depresses the foot pedal, the first fluid supply source 31 of the service flexure portion SBX supplies the fluid to the first fluid pressure chamber 30, and the fluid pressure in the first fluid pressure chamber 30 The end of the piston 24 is moved in the braking direction X1. Then, the brake disk 23 is pressed against the rotary disk 22, and the rotary shaft 26 is stopped.

When the worker operates the parking knob or the emergency stop button, the second fluid supply source 39 of the auxiliary brake unit PBX stops the supply of fluid to the second fluid pressure chamber 38. Then, the pressing body 36 moves in the braking direction X1 by the force of the biasing means 37, and moves the piston 24 in the braking direction X1. Then, the rotary disk 22 and the brake disk 23 are pressure-bonded, and the rotary shaft 26 is stopped.

As described above, the service brake, the parking brake, and the emergent brake can all be driven by the fluid pressure mechanism without using the mechanical link mechanism.

In the problem solving means according to claim 2, when the brake device is detached and attached for maintenance such as overhaul, the service brake portion SBX and the auxiliary brake portion PBX arranged adjacent to the end portion of the counter shaft 26 are sequentially detached and attached. This eliminates the need to remove the output shaft as in the past.

In the problem solving means according to the third aspect, the compression spring 47 bends from a desired position when the compression spring 47 is attached to the pressing body 36 or the rotational force of the rotary shaft 26 is transmitted during the break. Sometimes. At this time, the compression spring 47 is positioned between the housing 21 and the pressing body 36 by the positioning plate 48 fixed to the housing 21 to prevent its bending.

In the problem solving means according to claim 4, when the rotational force of the rotary shaft 26 is transmitted to the pressing body 36 at the time of intermittent braking, the rotation of the pressing body 36 is blocked by the restriction pin 43, and the compression spring 47. Prevent twisting.

[0026]

【Example】

 FIG. 1 is a sectional view of a wet multi-plate type brake device showing an embodiment of the present invention. As shown in the figure, the brake device of the present embodiment is of a wet multi-plate type having a composite structure of a service brake, a parking brake, and an emergency brake, all on the same axis.

The internal structure will be mainly described below. In the brake device of the present embodiment, the rotating disk 22 that rotates in the housing 21 of the transmission and the rotating disk 22 are brought into contact with each other to stop the rotation. A brake disc 23, a service brake unit SBX that presses the two discs 22 and 23 when the operator depresses the foot brake, and an auxiliary brake unit PBX that presses the discs 22 and 23 when parking or in an emergency. It is equipped with.

One end of the housing 21 is opened, and a back cover 21c is fixed to this opening via a bolt 21e. A rotation shaft (counter shaft) 26 of the transmission is rotatably mounted in the housing 21, and a rotary disk 22 is externally fitted and fixed to an end of the rotation shaft. A brake disk 23 is disposed in the vicinity of the rotary disk 22 so as to face the rotary disk 22 with a certain gap, and is slidably supported by the housing 21 via a disk mounting plate 23a. The service brake unit SBX and the auxiliary brake unit PBX are arranged between the rotary shaft 26 and the opening.

A step portion 25 is formed on the inner peripheral surface of the housing 21 on the side of the rotary shaft 26. The step 25 has a first slide hole 25b and a second slide hole 25c continuous with the first slide hole 25b and having a smaller diameter than the first slide hole 25b. The space between them is the urging chamber 25d.

The service brake unit SBX is arranged on a side opposite to the braking direction X 1 of the piston 24 when braking, and a piston 24 for bringing the brake disk 23 into contact with and separating from the rotary disk 22 along a rotary shaft 26. A first fluid supply source 31 for supplying a fluid (hereinafter, referred to as pressure oil) to the first fluid pressure chamber 30 is arranged adjacent to the end of the counter shaft 26.

The piston 24 is formed in a substantially disc shape, and is urged in the X2 direction by a wave spring 27 arranged between the outer edge of the piston 24 and the disc mounting plate 23a when not braking. .. A contact tray 28 is provided at the center of the rear surface of the piston 24 opposite to the braking direction X1 (hereinafter, referred to as X2 direction). The contact plate 28 is slidably fitted in the first sliding hole 25b.

As shown in FIG. 1, the first fluid pressure chamber 30 is a space surrounded by the edge of the abutment plate 28 of the piston 24 and the hole wall and bottom wall of the first sliding hole 25b. Then, it is connected to the port 30a on the outer peripheral surface of the housing 21 through the flow path 25e formed in the hole wall of the first sliding hole 25b, and is connected to the first fluid supply source 31.

As shown in FIG. 2, an existing hydraulic cylinder is used as the first fluid supply source 31 and supplies pressure oil to the first fluid pressure chamber 30 when the operator steps on the foot brake of the vehicle. Controlled.

As shown in FIG. 2, the auxiliary brake unit PBX is a negative type brake mechanism in which the supply of hydraulic pressure is stopped and the brake is applied only when the parking knob PN or the emergency stop button EN is operated. The piston 24 of the brake part SBX, a pressing body 36 that abuts against the rear surface of the piston 24 and presses it, a biasing means 37 that biases the pressing body 36 in the direction of abutting the piston 24, and the pressing body 36. And a second fluid supply source 39 for supplying a fluid to a second fluid pressure chamber 38 formed between the front surface on the piston 24 side and the housing 21.

The pressing body 36 is formed in a substantially disc shape, and on the piston 24 side thereof, a cylindrical convex portion 41 that contacts the contact tray 28 is formed and slides in the second sliding hole 25c. It is fitted inside freely.

The urging means 37 is several dozen coil compression springs 47 interposed between the back surface of the pressing body 36 and the back cover 21c of the housing 21 in the urging chamber 25d. Are arranged at regular intervals so as to uniformly urge the surface of the pressing body 36.

As shown in FIG. 1, the second fluid pressure chamber 38 is a space surrounded by the front wall and the side wall of the urging chamber 25 d and the front surface of the pressing body 36, and is a hole wall of the urging chamber 25 d. It is communicated with the port 38a on the outer peripheral surface of the housing 21 through the flow passage 25f formed in the second fluid supply source 39.

An existing hydraulic cylinder is used as the second fluid pressure supply source 39, and a second fluid pressure formed between the front surface of the pressing body 36 on the piston 24 side and the housing 21 when the brake is not operated. A fluid is supplied to the chamber 38, thereby separating the pressing body 36 and the piston 24 against the biasing means 37. On the other hand, during braking, when switching is performed with the parking knob or the emergency button, the supply of fluid to the second fluid pressure chamber 38 is controlled to be stopped.

Further, in this embodiment, a positioning plate 48 for mainly positioning the central portion of the compression spring 47 is internally fitted and fixed to the rear cover 21c of the housing 21. The positioning plate 48 is a circular plate having a through hole 49 formed therein in accordance with the coil diameter of the compression spring 47, and is fixed to the back cover 21c by a snap ring 50.

The reason for providing the positioning plate 48 is as follows. As described above, in this example, several tens of compression springs 47 are provided, so that the elastic force becomes large, and the braking force greatly changes depending on the tightening method and the spring behavior during braking. In this case, the following are examples of specific mounting defects of the compression spring 47.

1) The compression spring 47 may be tightened while falling down, and the urging force may be insufficient as a whole. In this case, there is a structural problem that the compression spring 47 cannot be seen from the outside even if the compression spring 47 is assembled in a tilted state, and it can be checked only by a bench test or the like.

2) The rotational force of the rotary shaft 26 may be transmitted to the pressing body 36 via the piston 24, the compression spring 47 may be bent, and the biasing force may be insufficient. That is, when the brake is applied intermittently, the piston 24 is rotated in the direction of rotation of the rotary disk 22 by the amount of backlash. As this continues, the pressing body 36 starts to rotate. As a result, since the compression spring 47 has one end fixed to the housing 21 and the other end rotated by the pressing body 36, the compression spring 47 bends, the regular biasing force becomes low, and the damping force becomes insufficient. Become. Therefore, in this embodiment, the positioning plate 48 is provided to prevent the compression spring 47 from falling.

Further, in this embodiment, rotation preventing means 42 for preventing the pressing body 36 from rotating with respect to the housing 21 is provided.

The rotation preventing means 42 is arranged so as to face a fitting hole 44 formed in the surface of the pressing body 36 orthogonally to the rotation direction and to the fitting hole 44 via the second fluid pressure chamber 38. The housing 21 includes an opposed hole 45, and a fitting pin 44 and a restriction pin 43 fitted in the opposed hole 45 to restrict the rotation of the pressing body 36. As a result, the rotation of the pressing body 36 is prevented during intermittent braking, and the compression spring 47 can be prevented from twisting.

In the figure, 21a is an oil supply port for lubricating and cooling the brake disks 22 and 23, 52 is a seal, 53 is a hub, and 54 and 55 are gears.

Next, the operating principle of the brake device of this embodiment will be described.

When the vehicle is not braked, the second fluid supply source 31 supplies pressure oil to the second fluid pressure chamber 38. Therefore, the pressing body 36 is biased in the X2 direction by the force of the area of the second fluid pressure chamber 38 facing the pressing body 36 against the force of the compression spring 47 of the biasing means 37. The piston 24 is biased in the X2 direction by the wave spring 27. Therefore, the rotary disk 22 and the brake disk 23 are in a separated state from each other, and the brake is in a non-braking state.

Here, when the worker depresses the brake pedal during traveling, the pressure oil from the first fluid pressure cylinder is sent to the first fluid pressure chamber 30. As a result, the piston 24 is moved in the braking direction X1 by the force of the area of the piston 24 by the pressure oil supplied to the first fluid pressure chamber 30. At this time, the pressing body 36 is separated from the piston 24 and remains stopped. Then, the piston 24 moves in the braking direction X1 against the wave spring 27 and presses the brake disc 23. Then, the brake disk 23 is pressed against the rotary disk 22. As a result, the hub 53, the rotary shaft 26, the gears 54 and 55, and the output shaft shift L1 are switched from the rotating state to the braking state, and the vehicle is stopped.

Then, when the worker again releases his / her foot from the foot pedal, the pressure oil to the first fluid pressure chamber 30 by the first fluid supply source 31 is cut and drained. As a result, the piston 24 is pushed in the X2 direction by the wave spring 27, and the rotary disk 22 and the brake disk 23 are released from each other. Therefore, the hub 53, the rotating shaft 26, the gears 54 and 55, and the output shaft shift L1 are switched from the braking state to the rotating state.

Next, the case where the parking brake is used will be described. When the operator operates the parking knob of the parking brake, the pressure oil from the second fluid supply source 39 to the second fluid pressure chamber 38 is cut and drained. As a result, the pressing body 36 moves in the braking direction X1 by the force of the compression spring 47 of the urging means 37 and comes into contact with the piston 24, and the piston 24 also resists the wave spring 27 and moves in the braking direction X1. Moving . As a result, the rotary disk 22 and the brake disk 23 are pressed against each other, and the hub 53, the rotary shaft 26, the gears 54 and 55, and the output shaft L1 cannot rotate, and the brake is applied.

At this time, if the brake is applied intermittently, the rotational force of the rotary shaft 26 may be transmitted to the pressing body 36 via the disks 22 and 23 and the piston 24. Since 42 is provided, rotation of the pressing body 36 can be prevented. Further, in addition to the provision of the positioning plate 48, the compression spring 47 can be prevented from falling and the biasing force of the biasing means 37 can be stabilized.

Next, when the vehicle is traveling with the parking brake released, the pressure oil from the second fluid supply source 39 is supplied to the second fluid pressure chamber 38 by a knob operation. Then, with the fluid pressure of the area of the second fluid pressure chamber 38 facing the pressing body 36, the pressing body 36 moves in the X2 direction against the compression spring 47 of the pressing body 36, and the piston 24 causes the pressing body 36 to move. Along with the movement, the wave spring 27 moves in the X2 direction. Then, the brake disk 23 and the rotary disk 22 are released from each other and are in a running state.

The above-described operation is the same for the emmergence brake.

From the above, the features of this embodiment are as follows.

(A) Since the parking brake or the emergency brake is a negative type in which the hydraulic pressure is turned on / off, it can be a one-touch parking brake such as a knob or a button. As a result, even if the clutch becomes worn in a long-term vehicle, the piston will automatically drive in, so the pressure can be kept constant and there is no need to adjust the brake.

(B) Since the service brake unit SBX and the auxiliary brake unit PBX are combined and arranged adjacent to the end portion of the counter shaft shaft 26, it is attached to the output shaft shaft like a skewer. In comparison, by removing the back cover 21d, the brake device can be easily attached / detached and maintained.

(C) Since the mechanical structures of the service brake, the parking brake, and the emergency brake are integrated, the number of parts can be reduced and the cost can be reduced.

(D) Since the positioning plate 48 for the compression spring 47 is provided, even if the compression spring 47 cannot be seen directly at the time of mounting, the compression spring 47 is prevented from falling down or bending. it can.

(E) Since the restriction pin 43 is attached between the pressing body 36 and the housing 21 as a detent for the pressing body 36, even if the pressing body 36 tries to rotate by continuous braking, the restriction pin 43 does It can prevent its rotation. Therefore, the rotational force of the rotary shaft 26 can be prevented from being transmitted to the compression spring 47, the compression spring 47 can be prevented from bending, the biasing force can be stabilized, and a certain braking force can be secured.

The present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention.

[0061]

[Effect of the device]

 As is apparent from the above description, according to claim 1 of the present invention, since the service brake, the parking brake, and the emergency brake are all integrated into one fluid pressure mechanism, a complicated mechanical link as in the conventional case is used. It is possible to perform the braking operation with a simple configuration without providing a mechanism. Therefore, the number of parts can be reduced.

Further, since the parking brake and the emergent brake are of a negative type, the pressure force of the brake disk and the rotary disk at the time of braking can be regulated by the urging force of the urging means, and the urging force of the vehicle can be used in an emergency. The braking force can always be stabilized.

According to claim 2 of the present invention, since the service brake portion and the auxiliary brake portion are arranged adjacent to the end portion of the counter shaft, the rear surface is attached to the output shaft in a skewered shape as compared with the conventional case. By removing the cover, the brake device can be easily attached / detached, maintenance, etc., and serviceability is improved.

According to the third aspect of the present invention, since the positioning plate is fixed to the housing, it is possible to prevent the compression spring from falling, stabilize the biasing force thereof, and secure the braking force.

According to claim 4 of the present invention, since the rotation preventing means including the restriction pin for preventing the rotation of the pressing body is provided, even if the pressing body tries to rotate by the continuous brake, the rotation preventing means does not prevent the pressing body from rotating. If the rotation of the compression spring can be prevented, the bending of the compression spring can be prevented, and the urging force of the compression spring can be stabilized, an excellent effect can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a wet multi-plate brake device showing an embodiment of the present invention.

FIG. 2 is a block diagram similarly showing the transmission of the braking force.

FIG. 3 is a diagram showing a mounting position in a vehicle in an example of a conventional wet multi-plate brake device.

FIG. 4 is a sectional view of relevant parts showing a parking brake or an emergent brake of the same.

FIG. 5 is a diagram showing a mounting position of the wet multi-plate brake device in the vehicle.

FIG. 6 is a sectional view of the same.

[Explanation of symbols]

 21 Housing 22 Rotating Disc 23 Brake Disc 24 Piston 26 Rotating Shaft 30 First Fluid Pressure Chamber 31 First Fluid Supply Source 37 Energizing Means 38 Second Fluid Pressure Chamber 39 Second Fluid Supply Source 42 Rotation Preventing Means 43 Control Pin 44 Fitting Dowel hole 47 Compression spring 48 Positioning plate SBX Service brake part PBX Auxiliary brake part X1 Braking direction

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Hideo Nasu 1-15-10 Kyomachibori, Nishi-ku, Osaka City Toyo Transporter Co., Ltd. (72) Akira Takeshita 1-15-10 Kyomachibori, Nishi-ku, Osaka Toyo Transport Machine Co., Ltd.

Claims (4)

[Scope of utility model registration request] 1. A rotary disk mounted on a rotary shaft in a housing, a brake disk that abuts on the rotary disk to stop the rotation of the rotary shaft, and both disks when an operator steps on a foot brake. A service brake unit for crimping, and an auxiliary brake unit for crimping both discs during parking or in an emergency are provided. And a first fluid supply source that supplies fluid to a first fluid pressure chamber that is sometimes arranged on the opposite side of the braking direction of the piston, and the auxiliary brake unit contacts the piston and the rear surface of the piston. A pressing body for pressing, an urging means for urging the pressing body in the direction of abutting the piston, and the pressing body when the brake is not operated. A second fluid supply source for supplying a fluid to a second fluid pressure chamber formed between the front surface on the piston side and the housing to separate the pressing body from the piston against the biasing means. Brake device. 2. The rotating disk according to claim 1 is fixed to an end portion of a counter shaft of a transmission, and the service brake portion and the auxiliary brake portion according to claim 1 are arranged adjacent to the end portion of the counter shaft. Brake device characterized by 3. The urging means according to claim 1 is composed of a plurality of compression springs, and is positioned in the housing according to claim 1 between the housing and the pressing body so as to prevent the compression spring from collapsing. A braking device characterized by a fixed plate. 4. The braking device according to claim 1,
Rotation preventing means for preventing rotation of the pressing body is provided, and the rotation preventing means is fitted in the fitting hole formed in the pressing body in parallel with the rotation axis direction and fixed in the housing. And a regulation pin that regulates the rotation of the pressing body.