JPH031629Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a shaft brake device for a piston motor used for driving a hydraulic excavator.

As a piston motor, for example, the one shown in FIG. 1 is known.

A cylinder block h is rotatably provided in a housing g, a piston j is fitted into a cylinder hole i of the cylinder block h to form a cylinder chamber k, and the piston j is swingably connected to a drive shaft e. , the piston j is reciprocated by supplying pressure oil to the cylinder chamber k through an inlet port formed on the valve plate l, and causing the pressure oil in the cylinder chamber k to flow out to the tank side through an outlet port formed on the valve plate l. The drive shaft e is configured to be rotated by the drive shaft e.

In such a piston motor, if an external force is applied to the drive shaft e without supplying pressure oil into the cylinder chamber k, the drive shaft e will rotate, so when used for example to drive a hydraulic excavator, Since the drive shaft e rotates due to external force when the vehicle is stopped on a slope, etc., a shaft brake device is provided to mechanically fix the drive shaft e to ensure that the vehicle stops.

For example, as shown in FIG. 1, a spring a presses a brake piston b, and the brake piston b presses a plate c provided on the side of the drive shaft e to a disk d provided on the side of the cover m. A shaft brake device is known in which the brake is released by braking the engine, supplying pilot pressure oil to the oil chamber f, and moving the brake piston b against the spring a.

As mentioned above, conventional shaft brake devices require pilot pressure oil to release the brakes, and cannot be released by manual operation.

For this reason, when used as a driving force for a hydraulic excavator, when the engine fails and the vehicle is towed due to engine failure, the shaft brake system is activated without generating pilot pressure oil. Since the brakes cannot be released, the vehicle cannot be towed, and in that case, a simple hydraulic power source must be provided or the piston motor must be removed, which is very inconvenient.

In order to solve this problem, for example,
As shown in Japanese Patent No. 42878, a shaft brake device has been proposed in which a brake piston is moved in a direction against a spring by a bolt screwed from the outside to release the brake.

However, this shaft brake device only moves the brake piston to separate the plate and disk so that the drive shaft can rotate, and a hydraulic brake valve is installed in the hydraulic circuit connected to the inlet port and outlet port of the piston motor. In this case, the drive shaft cannot be rotated by external force.

In other words, the hydraulic brake valve communicates and blocks the first passage connected to the inlet port and the second passage connected to the outlet port, and when the first passage or the second passage becomes high pressure, the communication position is closed by the spring force. Therefore, as mentioned above, if the engine fails and no oil pressure is generated, the hydraulic brake valve will be in the cutoff position, the first passage and the second passage will be blocked, and the inlet port and outlet port will be cut off. .

For this reason, the pressure oil is trapped in the cylinder chamber k, and the piston j cannot reciprocate, and even if an external force acts on the drive shaft e, the piston j supports the external force, so the drive shaft e It becomes impossible to rotate. In other words, when the hydraulic brake valve is in the cutoff position, it has a braking function.

The present invention was developed in view of the above circumstances, and its purpose is to create a piston motor that can be operated manually from the outside to move the brake piston against a spring, and also to release the brake function of the hydraulic brake valve. An object of the present invention is to provide a shaft braking device.

Hereinafter, the present invention will be explained with reference to FIG. 2 and subsequent figures.

In the drawings, reference numeral 1 denotes a cover, and a housing 2 is fixed to the end of the cover 1 to form a motor case B having a space A. Shaft support part 3 of cover 1
A drive shaft 5 is supported via a bearing 4, and a flange 6 is formed at the inner end of the drive shaft 5. being done. Said motor case B
A piston motor assembly 8 is accommodated in the space A.

The piston motor assembly 8 includes a motor case B.
A cylinder block 30 is rotatably provided in a space A, and a piston 32 is fitted into a cylinder hole 31 of the cylinder block 30 to form a cylinder chamber 33, and the piston 32 is pivoted to the drive shaft 5. When the cylinder block 30 rotates, the cylinder chamber 33 is sequentially communicated with a substantially semicircular inlet port 35 and an outlet port 36 formed in the valve plate 34 and shown in FIG. 3.

The inlet port 35 and the outlet port 36 are connected to a first passage 3 formed in the housing 2 as shown in FIG.
7, each communicates with the second passage 38, and the first passage 3
7 and the second passage 38 are composed of port side passages 37 ₁ , 38 ₁ communicating with the inlet port 35 and outlet port 36 and outflow/inflow side passages _{37 2 , 38 2 .} The side passages 37 ₂ , 38 ₂ are connected from the inflow and outflow side passages 37 ₂ , 38 ₂ to the port side passage 37 ₁ ,
The check valves 39 that allow pressure oil flow to the ports 38 ₁ communicate with each other, and the port side passages 37 ₁ , 3 communicate with each other.
8 ₁ and the inflow and outflow side passages 37 ₂ and 38 ₂ are the housing 2
They are communicated and shut off by a spool 40 provided at the spool 40, thereby forming a hydraulic brake valve 41.

The spool 40 has a first small diameter portion 40a that communicates and blocks the port side passage 37 ₁ of the first passage 37 and the inflow/outflow side passage 37 ₂ , and the port side passage 38 ₁ of the second passage 38 and the inflow/outflow side passage 38 . A _second small diameter portion 40b is formed that connects and blocks the spool 40.
is a pair of left and right springs 42, 42 that connect each port side passage 3.
7 ₁ , 38 ₁ and the inflow/outflow side passages 37 ₂ , 38 ₂ , that is, the first passage 37 and the second passage 38 are held in a position where the pressure oil is supplied to the pressure receiving chamber 44 from the pore 43 . End face of spool 40 and retainer 4
Pressure oil flows into the gap between the spool 40 and the spool 40.
moves to the left or right and connects the port side passage 38 ₁ and the inflow/outflow side passage 38 ₂ of the second passage 38 or the port side passage 37 ₁ and the inflow/outflow side passage 37 ₂ of the first passage 37 to the second small diameter portion 40b. Or communicating through the first small diameter portion 41a,
and the inflow/outflow side passage 37 ₂ of the first passage 37 or the second
The inlet/outlet side passage 38 ₂ of the passage 38 is connected to the introduction port 45
It is designed to communicate with. For example, the first passage 37
When pressure oil flows into the inflow and outflow side passage 37 ₂ of the spool 40, the spool 40 moves to the left and communicates the port side passage 38 ₁ and the inflow and outflow side passage 38 ₂ of the second passage 38, thereby communicating the second passage 38. Outflow/inflow side passage 37 of first passage 37
The pressure oil that has flowed into _{the first} port 35 flows through the check valve 39 and the port side passage ₃₇₁ , and
The pressure oil flows into the introduction port 45 at the small diameter portion 40a of the pressure oil, and the pressure oil from the outlet port 36 flows out from the second passage 38.

A cylinder portion 9 is formed on the inner peripheral portion of the cover 1 as shown in FIG.
A brake piston 10 is slidably housed within the brake piston 10, and a ring 1 is attached to the brake piston 10.
1 is fixed, the outer periphery of this ring 11 is spline engaged with a spline part 12 provided on the inner periphery of the cover 1, and a lining 13 is attached to the conical surface of the inner periphery of the ring 11. There is.

The brake piston 10 is biased by a spring 14, and the lining 13 of the ring 11 is pressed against the conical surface 7 of the drive shaft 5 to brake the drive shaft 5 so as not to rotate.
The brake is released by moving the brake piston 10 against the spring 14 using the pressure oil supplied to the first passage. When pressure oil is supplied to 37, the spool 40 moves, and a part of the pressure oil passes through the introduction port 45 and the guide hole 16 to the oil chamber 15.
It is designed so that it can flow into the air and release the brake.

As shown in FIG. 4, a pair of screw holes 18, 18 are formed in the end surface 17 of the brake piston 10 facing the housing 2. The insertion holes 19, 19 of the first passage 3
7. The first passage 37 and the second passage 38 are formed to be open to the second passage 38, and the first passage 37 and the second passage 38 are communicated with the pair of insertion holes 19 and the space A of the motor case B, and A pair of screw holes 20, 20 are provided in the housing 2 and are connected to the pair of insertion holes 19, 19.
The tip of the plug 21, which is formed concentrically with the screw hole 20 and is normally screwed into the screw hole 20, is tightly fitted into the insertion hole 19 to close the insertion hole 19, thereby connecting the first passage 37 and the second passage 37. The passage 38 is made not to communicate. In FIG. 4, 26 is a seal.

Therefore, when manually releasing the shaft brake device, remove the plug 21 and insert it into the insertion hole 1 as shown in Figure 5.
9, screw the bolt 22 into the screw hole 18, and pull the bolt 22 against the pressing force of the spring 14 to move the brake piston 10 and line the conical surface of the ring 11. 13 from the conical surface 7 of the drive shaft 5 to release the brake.

The bolt 22 has a smaller diameter than the insertion hole 19, and a gap 23 is formed between the insertion hole 19 and the bolt 22 as shown in FIG.
Passage 37 and space A and second passage 38 and space A
are connected to each other.

As a result, even if the first passage 37 and the second passage 38 are blocked by the hydraulic brake valve 41, the first passage 37 and the second passage 38 are communicated through the space A of the motor case B and the gap 23. valve plate 3
Since the inlet port 35 and the outlet port 36 formed in 4 are in communication and the braking function of the hydraulic brake valve 41 is released, the piston 32 can smoothly reciprocate and the above-mentioned shaft braking device is released. Together, the drive shaft 5 can be rotated by external force.

Therefore, when a piston motor equipped with a hydraulic brake valve 41 is used for driving a hydraulic excavator, the plug 21 is removed and the bolt 22
Just screw them together and pull them to tow the vehicle.

Since the present invention is constructed as described above, the pair of plugs 21 and 21 are removed, and the pair of bolts 22 and 22 are screwed into the screw hole 18 through the screw hole 20 and the insertion hole 19, and the brake piston 10 is attached to the spring 14. By moving the drive shaft 5 against the brake, the brake can be released from the drive shaft 5. Moreover, since the bolt 22 has a smaller diameter than the insertion hole 19, a gap 23 is formed between the bolt 22 and the insertion hole 19, and a gap 23 is formed between the bolt 22 and the insertion hole 19. Therefore, the first passage 37 and the second passage 38 communicate with the space A of the motor case B, and the first passage 37 and the second passage 38 communicate with each other, so that the brake function of the hydraulic brake valve 41 can be released.

Therefore, by removing the plug 21 and inserting and screwing the bolt 22, the brake piston 10 can be manually operated from the outside to move against the spring 14 to release the brake, and the hydraulic brake valve 41 can be canceled.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a piston motor equipped with a conventional shaft brake device, FIG. 2 is a vertical cross-sectional view of a piston motor equipped with a shaft brake device according to an embodiment of the present invention, and FIG. Sectional view along the line, 4th
The figure is a sectional view taken along the line of FIG. 3, and FIG. 5 is an explanatory view at the time of brake release operation. 1 is a cover, 2 is a housing, 5 is a drive shaft, 10 is a brake piston, 14 is a spring,
15 is an oil chamber, 18 is a screw hole, 19 is an insertion hole, 20
is a screw hole, 21 is a plug, 22 is a bolt, 23 is a gap, 30 is a cylinder block, 31 is a cylinder hole, 32 is a piston, 33 is a cylinder chamber,
34 is a valve plate, 35 is an inlet port, 36 is an outlet port, 37 is a first passage, 38 is a second passage, 41 is a hydraulic brake valve, A is a space, and B is a motor case.

Claims (1)

[Claims for Utility Model Registration] The cover 1 and the housing 2 constitute a motor case B having a space A, and a cylinder chamber 33 is formed by fitting a piston 32 into a cylinder hole 31 of a cylinder block 30 provided in the space A. The piston 32 is pivotally connected to the drive shaft 5 supported on the cover 1, and the cylinder chamber 33 is sequentially communicated with an inlet port 35 and an outlet port 36 formed in the valve plate 34. 3
5 communicates with a first passage 37 formed in the housing 2, and the outlet port 35 communicates with a second passage 38 formed in the housing 2, and the outlet port 35 communicates with a second passage 38 formed in the housing 2.
7. In a piston motor equipped with a hydraulic brake valve 41 that communicates and blocks the second passage 38, a brake piston 10 is provided in the space A of the motor case B, and the brake piston 10 brakes the drive shaft 5 with a spring 14. the brake piston 10 using the pressure oil in the oil chamber 15.
A pair of inserts are inserted into the housing 2 to communicate the first passage 37 and the second passage 38 with the space A of the motor case B. Holes 19, 19 and first passage 37, second
A pair of screw holes 20 and 20 are respectively formed concentrically to open a passage 38 on the outer surface of the housing 2, and a pair of screw holes 1 are formed in the brake piston 10.
8 and 18 are formed to face the pair of insertion holes 19 and 19, and normally the pair of insertion holes 19 and 19 are closed with a pair of plugs 21 and 21 screwed into the pair of screw holes 20 and 20. When the brake is released, a bolt 22 having a smaller diameter than the insertion hole 19 is inserted through the pair of screw holes 20, 20 and screwed into the pair of screw holes 18, 18 to secure the brake piston. 1. A shaft brake device for a piston motor, characterized in that the shaft brake device 10 is configured to move against a spring 14.