JP2002349508A - Brake device of hydraulic motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake device for hydraulic motor capable of braking it a certain time after the supply of pressure oil to the motor is stopped and realizing a small-sized device construction and a reduction of the number of components. SOLUTION: The brake device of a hydraulic motor is composed of a negative brake 4 including a brake piston 29, first oil chamber 8, and second oil chamber 12, a hydraulic source 9, a selector valve 5 to make supply and exhaust of the pressure oil from the source 9 to/from the brake 4, and a throttle 7 to work when the pressure oil is to be exhausted from the brake 4, wherein a first oil chamber 8 to be supplied with pressure oil when the braking of the hydraulic motor 2 is disengaged and a second oil chamber 12 to form an accumulator mechanism are provided in the piston 29 part of the negative brake 4, and the arrangement further includes a converging means to converge the pressure oil from the first chamber 8 with the pressure oil from the second chamber 12 when brake is to be applied to the hydraulic motor 2 and a hydraulic motor block 1 in which the negative brake 4 and converging means are consolidated with the hydraulic motor 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake device for a hydraulic motor provided on a construction machine such as a hydraulic excavator and provided with a negative brake and an accumulator mechanism.

[0002]

2. Description of the Related Art At the same time as the supply of hydraulic oil to a hydraulic motor having a negative brake is stopped, the hydraulic motor is braked by the negative brake. Was forced to stop. When such a situation occurs, the stopping feeling is deteriorated, and the negative brake components are worn.
In addition, there is a problem that the wear of the negative brake components accelerates the reduction of the braking ability.

[0003] Under these circumstances, Japanese Utility Model Application Laid-Open No.
The technology described in Japanese Patent Application Publication No. 090 has been proposed. FIG. 9 is a hydraulic circuit diagram showing a conventional hydraulic motor brake device described in the above-mentioned publication.

[0004] The prior art shown in FIG.
A rotary plate, that is, a disk 75 is integrally provided on the output shaft of the motor 3, and a pad 76 that can contact the disk 75 is
The negative brake 74 is constituted by energizing at 7. A brake pipe 78 is connected to an oil chamber of a brake cylinder arranged to oppose the spring 77, and a switching valve 79 is provided between the brake pipe 78 and a hydraulic source and a tank (not shown). . A throttle 80 is provided in the tank line downstream of the switching valve 79. An accumulator 71 containing a spring 72 is connected to a portion of the brake line 78 located between the negative brake 74 and the switching valve 79.

In this prior art, when the hydraulic motor 73 is driven, the switching valve 79 is switched to the upper position, whereby the pressure oil of the hydraulic source is supplied to the oil chamber of the brake cylinder via the brake line 78 and the force of the spring 77 is applied. Pad 76 against
Moves in the direction away from the disk 75, and the braking on the hydraulic motor 73 is released. At the same time, the pressure oil guided to the brake line 78 is supplied to the accumulator 71 and accumulated in the accumulator 71.

When the hydraulic motor 73 stops, the switching valve 79
Is switched to the lower position as shown in FIG. 9, and the pressure oil discharged from the oil chamber of the brake cylinder and the accumulator 7
The pressure oil discharged from 1 is joined via the brake line 78 and returned to the tank via the switching valve 79 and the throttle 80. As a result, the brake cylinder is actuated with a time lag from the time when the supply of the pressure oil for rotating the hydraulic motor 73 is stopped, and the pad 76 is moved by the force of the spring 77 to the disk 75.
, The rotation of the hydraulic motor 73 can be stopped. Therefore, the hydraulic motor 73 can be braked by the negative brake 74 after the rotation of the hydraulic motor 73 due to inertia is almost stopped.

[0007] With this configuration, it is possible to prevent the deterioration of the stop feeling, which has been concerned up to that point, and to suppress the wear of the negative brake components.

[0008]

In the above-mentioned prior art, the mutual operation timing of the separately provided brake cylinder and the accumulator 71 is not considered. For this reason, there are dimensional errors in manufacturing the brake cylinder and the accumulator 71 and the springs 77 and 72.
There is a concern that the pressure oil may be discharged from the brake cylinder before the discharge of the pressure oil from the accumulator 71 due to a variation in the setting of the force or the like.

When such a situation occurs, a braking force is applied to the rotating hydraulic motor 73, and as a result, as described above, the stopping feeling deteriorates, the wear of the negative brake components, and the braking performance deteriorates. This will result in an early decline.

Further, in the above-described conventional technique, the negative brake 74 including the brake cylinder is connected to the hydraulic motor 73.
However, the accumulator 71 is provided separately from the hydraulic motor 73, that is, it is configured as an independent hydraulic device, and therefore, the pipeline constituting the brake circuit 78 is also long, and the entire device is Upsizing,
There is a problem that the number of parts is increased and the manufacturing cost is likely to be increased accordingly.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described prior art, and has as its object to provide a hydraulic motor using a negative brake after a predetermined time has elapsed from when the supply of hydraulic oil to the hydraulic motor is stopped. It is an object of the present invention to provide a hydraulic motor brake device capable of realizing the braking of the hydraulic motor and realizing the miniaturization of the device and the reduction of the number of parts.

[0012]

In order to achieve the above object, the invention according to claim 1 of the present application is directed to a negative brake for braking a hydraulic motor, and a hydraulic oil for releasing braking of the hydraulic motor by the negative brake. , A switching valve for supplying and discharging the hydraulic oil from the hydraulic source to the negative brake, a throttle working when discharging the hydraulic oil from the negative brake, and a hydraulic oil for releasing the braking of the hydraulic motor. A hydraulic fluid brake device having an accumulator mechanism for discharging the hydraulic fluid, wherein a first oil chamber to which a pressure oil from the hydraulic pressure source is supplied to a brake piston portion provided in the negative brake when braking of the hydraulic motor is released. The second forming the accumulator mechanism
In addition to providing an oil chamber, when braking the hydraulic motor,
A converging means for converging the pressure oil discharged from the first oil chamber and the pressure oil discharged from the second oil chamber is provided, and includes the brake piston, the first oil chamber, and the second oil chamber. A hydraulic motor block is provided in which the negative brake and the joining means are integrated with the hydraulic motor.

According to the first aspect of the present invention, when the hydraulic motor is stopped from the driving state, the pressure oil discharged from the first oil chamber with the operation of the brake piston of the negative brake, and the accumulator mechanism The pressure oil discharged from the second oil chamber which forms the pressure is merged via the joining means, returned to the tank via the switching valve and the throttle, and the flow of the pressure oil returned to the tank by the action of the throttle is slow. Because
The operation of the negative brake and the operation of the accumulator mechanism, that is, the joining of the pressure oil discharged from the second oil chamber to the pressure oil discharged from the first oil chamber can be performed almost at the same time. Therefore, when the hydraulic motor is stopped, braking of the hydraulic motor by the negative brake can be reliably realized after a predetermined time has elapsed since the supply of the pressure oil to the hydraulic motor was stopped. The first oil chamber and the second oil chamber are provided in the brake piston even if the pressure oil in the first oil chamber is discharged before the pressure oil in the second oil chamber forming the accumulator mechanism. From
The brake piston returns to the position where the hydraulic motor is braked after both the hydraulic oil in the first hydraulic chamber and the hydraulic oil in the second hydraulic chamber have been discharged, and after a predetermined time has elapsed from the stop of the supply of the hydraulic oil to the hydraulic motor. The hydraulic motor can be braked by the negative brake.

A negative brake including a brake piston, a first oil chamber, and a second oil chamber forming an accumulator mechanism;
Since a joining means for joining the pressurized oil discharged from the oil chamber and the pressurized oil discharged from the second oil chamber is included, the size of the apparatus can be reduced and the number of parts can be reduced.

[0015] The invention according to claim 2 of the present application is configured such that, in the invention according to claim 1, a first check valve that allows only the inflow from the tank to the second oil chamber is provided.

According to the second aspect of the present invention, when the braking of the hydraulic motor is released, the pressure oil from the hydraulic source is supplied to the first hydraulic motor.
When the brake piston moves while being supplied to the oil chamber, the first
Pressure oil from the tank is supplied to the second oil chamber via the check valve.

The invention according to claim 3 of the present application is the invention according to claim 2, wherein the first check valve is provided in the hydraulic motor block.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the merging means is provided in accordance with a differential pressure between the pressure of the second oil chamber and the pressure of the first oil chamber. It is configured to include a relief valve that operates and joins the pressure oil discharged from the first oil chamber and the pressure oil discharged from the second oil chamber.

According to the fourth aspect of the present invention, when the hydraulic motor is braked, when the pressure difference between the pressure in the second oil chamber and the pressure in the first oil chamber becomes equal to or higher than a predetermined pressure, the relief valve is operated. Is activated, and the pressure oil discharged from the second oil chamber via the relief valve and the pressure oil discharged from the first oil chamber merge.

The invention according to claim 5 of the present application is the invention according to claim 4, wherein the relief valve is provided in the hydraulic motor block.

The invention according to claim 6 of the present application is the invention according to claim 1, wherein the joining means includes a second check valve that allows only the flow of the pressure oil discharged from the second oil chamber. It is configured to include.

According to the sixth aspect of the present invention, when the hydraulic motor is braked, the pressure oil discharged from the second oil chamber and the pressure oil discharged from the first oil chamber via the second check valve. Merges with oil.

According to a seventh aspect of the present invention, in the sixth aspect, the second check valve comprises a check valve with a spring.

According to an eighth aspect of the present invention, in the sixth or seventh aspect, the second check valve is provided in the hydraulic motor block.

According to a ninth aspect of the present invention, in the first aspect of the present invention, there is provided a switching position enabling supply of pressurized oil to the first oil chamber, and a switching position for discharging the pressure oil from the first oil chamber. And a second switching valve having a switching position where the pressure oil discharged from the second oil chamber and the pressure oil discharged from the second oil chamber are joined.

According to the ninth aspect of the present invention, when the braking of the hydraulic motor is released, the hydraulic oil from the hydraulic source is supplied to the first oil chamber via the second switching valve to move the brake piston. Then, the braking on the hydraulic motor is released. Further, when the hydraulic motor is braked, the pressure oil discharged from the second oil chamber and the pressure oil discharged from the first oil chamber join via the second switching valve with the return operation of the brake piston.

According to a tenth aspect of the present invention, in the ninth aspect, the second switching valve is provided in the hydraulic motor block.

According to the third, fifth, eighth, and tenth aspects of the present invention, it is possible to realize a more effective downsizing of the apparatus and a reduction in the number of parts.

According to an eleventh aspect of the present invention, in the first aspect, the negative brake includes a brake piston, a spring for biasing the brake piston, and an output shaft of the hydraulic motor. A rotating plate that rotates with the rotation, and provided to face the rotating plate,
The brake piston includes a fixed plate that is pressed against the rotating plate as the brake piston moves by the spring, and the brake piston has three cylindrical portions having different diameters from each other, and is formed by these cylindrical portions. One of the two steps is provided with the first oil chamber and the other is provided with the second oil chamber.

According to the eleventh aspect of the present invention, when the hydraulic motor is braked, the brake piston is urged by the force of the spring, whereby the rotating plate and the fixed plate are brought into pressure contact with each other, and the hydraulic motor is braked. Kept in state.

When the hydraulic motor is driven, the pressure oil is guided to the first oil chamber, whereby the brake piston moves against the force of the spring described above, whereby the rotary plate separates from the fixed plate and the hydraulic motor is driven. Braking is released. At this time, the pressure oil is also supplied to the second oil chamber forming the accumulator mechanism, and the brake piston moves against the force of the above-described spring to accumulate pressure.

When the hydraulic motor is stopped from the driving state, the pressure oil discharged from the second oil chamber forming the accumulator mechanism and the pressure oil discharged from the first oil chamber join to switch the switching valve. , Returned to the tank via the throttle.

At this time, when the supply of the pressure oil to the hydraulic motor is stopped by realizing the merge of the pressure oil discharged from the second oil chamber and the pressure oil discharged from the first oil chamber as described above. Therefore, the negative brake is activated after a predetermined time has elapsed, and the brake piston is moved by the force of the spring described above, so that the rotating plate and the fixed plate are brought into pressure contact with each other, and the hydraulic motor is braked.

According to the eleventh aspect of the present invention, since the first oil chamber and the second oil chamber are formed in the cylindrical portion of the brake piston, the first oil chamber and the second oil chamber are formed by machining the brake piston. A room can be provided and the production is easy.

[0035]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a hydraulic motor brake device according to an embodiment of the present invention.

FIG. 1 is a hydraulic circuit diagram showing a first embodiment of a hydraulic motor brake device according to the present invention, and FIG. 2 is a sectional view of a main part showing a basic structure of a hydraulic motor provided in the first embodiment shown in FIG. FIG. 3 is a cross-sectional view showing a configuration of a main part of the first embodiment shown in FIG.

As shown in FIG. 1, the hydraulic motor block 1
Includes a negative brake 4 for braking the rotation of the rotary shaft 3 of the hydraulic motor 2, a switching valve 5, a check valve 6 provided in parallel with each other, and a first oil chamber 8 included in the negative brake 4 via a throttle 7. The tank 10 is selectively connected to a hydraulic pressure source 9 that supplies pressure oil for release to the tank 10. The first oil chamber 8, the brake line 11 for communicating with the check valve 6 and the throttle 7, and the second oil chamber 12 included in the negative brake 4 are connected to the relief valve 13 included in the merging means.
Is connected via. Further, a brake pipe line 14 included in a joining means for connecting the second oil chamber 12 and the relief valve 13 is connected to the motor drain 15 via a first check valve 16. The hydraulic motor 2 is connected to main pipes 17A and 17B for supplying high-pressure oil for motor rotation.

The above-described relief valve 13 is provided in the hydraulic motor block 1 together with the brake lines 11 and 14, the check valves 6 and 16, and the throttle 7, and the pressure of the second oil chamber 12 and the pressure of the first oil chamber 8 are provided. Is set as a pilot pressure, and when the pressure difference becomes equal to or more than a predetermined pressure, the inflow of oil from the brake line 14 to the brake line 11 is permitted.

The above-described hydraulic motor 2 has a structure shown in FIG.

The high-pressure oil for motor rotation flowing from the main pipe 17A (17B) is supplied to the piston 21 through the head 18, the valve plate 19, and the cylinder block 20.
The hydraulic reaction force of the piston 21 acts on the swash plate 22 provided obliquely with respect to the rotating shaft 3, and a rotational torque is generated on the piston 21. This rotational torque is applied to the cylinder block 20.
Is transmitted to the output shaft 3 via the. The output shaft 3 is a bearing 2
It is rotatably supported by 4 and 25.

As shown in FIG. 3, the negative brake 4 includes a fixed plate 27 whose rotation with respect to the motor casing 26 is restricted, and a rotary plate 28 which rotates integrally with the cylinder block 20 via a brake piston 29. Spring 3
The structure is such that they can be pressed against each other by zero force. As shown in FIG. 3, each of the brake piston 29 and the motor casing 26 has a cylindrical portion having three different diameters.
And the second oil chamber 12.

The parallel structure of the check valve 6 and the throttle 7 shown in FIG. 1 is similar to that shown in FIG.
This is realized by the poppet 34 with a throttle having the following. The throttled poppet 34 is urged by a spring 35 having a very small force.

As shown in FIG. 3, the relief valve 13 shown in FIG. 1 includes a poppet 36 having a pressure receiving area SP of a seat portion and a spring 37 for urging the poppet 36.

As shown in FIG. 3, the first check valve 16 shown in FIG. 1 comprises a poppet 38 and a spring 39 having a very small force for urging the poppet 38.

The operation of the first embodiment configured as described above is as follows.

When the hydraulic motor 2 is started, when the switching valve 5 is switched to the right position in FIG. 3 at the same time as supplying the pressure oil to the main pipeline 17A (17B) when the hydraulic motor 2 is started, the pressure oil of the hydraulic source 9 is switched. The throttled poppet 34 is supplied to the throttled poppet 34 via the valve 5, and is pushed upward in FIG. 3 to be supplied to the first oil chamber 8 via the brake line 11.

The pressure oil at this time acts on the poppet 36 so as to close the poppet 36.
6 remains closed, and no pressure oil is introduced into the second oil chamber 12. Accordingly, the pressure oil for releasing the brake is supplied only to the first oil chamber 8, and the brake piston 29 overcomes the force of the spring 30 and moves upward in the figure. At this time, the motor drain 1 is connected to the second hydraulic chamber 12 through the first check valve 16.
5 oils are supplied.

Here, the force of the spring 30 when the brake piston 29 is at the position shown in FIG.
The force of the spring 30 when the valve 9 moves upward is F2, the pressure receiving area of the first oil chamber 8 is SA, the pressure of the first oil chamber 8 when the brake piston 29 starts to move is PA1, and the pressure at the end of the movement is Assuming that PA2, PA1 = F1 / SA (1) PA2 = F2 / SA (2)

When the braking is released, the throttled poppet 34 moves upward in FIG. 3, so that the throttle 7 does not operate.

As described above, when the hydraulic motor 2 is started, when the braking of the hydraulic motor 2 is released, the braking of the hydraulic motor 2 is promptly released at the same time as the motor is started, and the motor generated due to the braking release delay at the time of starting. A satisfactory motor rotation function can be obtained without causing problems such as rotation delay, noise due to drag at the time of braking, and reduction in braking performance due to wear of the sliding portion.

[Motor Stop] When the hydraulic motor 2 stops, when the supply of the pressure oil to the main pipe 17A (17B) is stopped and the switching valve 5 is switched to the left position in FIG. When the supply is cut off, the brake piston 29 tends to move downward in FIG. At this time, the oil discharged from the first oil chamber 8 is supplied to the throttled poppet 34 via the brake line 11, and moves the throttled poppet 34 to the position shown in FIG. Therefore, the discharged oil is returned to the tank 10 via the throttle 7. The oil discharged from the second oil chamber 12 acts on the poppet 38 so as to close the poppet 38 and does not flow out to the motor drain 15. on the other hand,
With respect to the poppet 36, the poppet 36 acts to push the poppet 36 upward in the drawing, and the oil discharged from the second oil chamber 12 opens the poppet 36 and flows into the brake line 11, and the oil from the first oil chamber 8 It merges with the discharged oil and is discharged to the tank 10 through the throttle 7.

As described above, in this embodiment, after the supply of the release pressure oil is stopped, the second oil chamber 12 functions as an accumulator mechanism, and the pressure oil discharged from the second oil chamber 12 and the first oil
By joining the pressure oil discharged from the oil chamber 8,
The amount of oil discharged through the throttle 7 is increased. As a result, the time until the braking force is applied to the hydraulic motor 2 can be set longer.

As described above, after the supply of the pressure oil for braking release is stopped, the brake piston 29 moves downward in FIG.
The oil in the second oil chamber 12 is supplied to the poppet 36 through the brake line 14 and pushes the poppet 36 open. However, since the spring 37 acts on the poppet 36, the second oil chamber 12 and the brake The pressure in the pipe 14 has a higher value than the pressure in the first oil chamber 8 and the brake pipe 11.

The force of the spring 30 when the brake piston 29 is initially at the position shown in FIG. 3 is F1, and the force of the spring 30 when the brake piston 29 moves to the upper end is F1.
2. The force of the spring 37 at the set position in FIG.
3. The pressure receiving area of the first oil chamber 8 is SA, the pressure receiving area of the second oil chamber 12 is SB, and the pressure of the first oil chamber 8 at the start of movement of the brake piston 29 when shifting from the brake release state to the braking operation. PA3, the pressure of the first oil chamber 8 at the end of the movement, ie, the position shown in FIG. 3, is PA4. Similarly, the pressure of the second oil chamber 12 at the start and end of the movement is PB3, PB4, and the poppet 3.
Assuming that the pressure receiving area of the sheet portion of No. 6 is SP, F2 = PA3 × SA + PB3 × SB (3) F3 + PA3 × SP = PB3 × SP (4) F1 = PA4 × SA + PB4 × SB (5) F3 + PA4 × SP = PB4 × SP ( 6) From equations (3) and (4), PA3 = (F2−F3 × SB / SP) / (SA + SB) (7) PB3 = PA3 + F3 / SP = (F2−F3 × SB / SP) / (SA + SB) + F3 / SP (8) From equations (5) and (6), PA4 = (F1−F3 × SB / SP) / (SA + SB) (9) PB4 = PA4 + F3 / SP = (F1−F3 × SB / SP) / (SA + SB) + F3 / SP (10)

From the equations (7) to (10), the pressure in the second oil chamber 12 and the brake line 14 is always higher than the pressure in the first oil chamber 8 and the brake line 11 by a value corresponding to F3 / SP. You can see that.

The limiting condition satisfying the above expression is PA>
0, and from equation (9), it is necessary to satisfy F1> F3 × SB / SP (11). It can be seen that the pressure in the first oil chamber 8 can be controlled to a very small value by setting appropriate values F1, F2, F3, SA, SB, SP within a range satisfying this condition.

As described above, according to the present embodiment, the pressure in the brake line 11 and the first oil chamber 8 acting on the throttle 7 that controls the moving speed of the brake piston 29 can be controlled to a small value. The time until the braking force is applied to the hydraulic motor 2 can be set long.

As described above, in the present embodiment, after the supply of the brake release hydraulic oil is stopped, the hydraulic oil discharged from the second hydraulic chamber 12 forming the accumulator mechanism and the hydraulic oil discharged from the first hydraulic chamber 8 are stopped. The pressure oil that flows through the throttle 7 can be increased, and the brake oil acting on the throttle 7 that controls the moving speed of the brake piston 29 can be increased. Pipe line 11 and first oil chamber 8
Can be controlled to a small value (reducing the throttle differential pressure), and the time until the braking force is applied to the hydraulic motor 2 can be set long.

In the first embodiment configured as described above, after the supply of the pressure oil to the hydraulic motor 2 is stopped, the pressure oil is discharged from the first oil chamber 8 almost at the same time. It is possible to cause the pressure oil discharged from the second oil chamber 12 to merge with the pressure oil discharged from the first oil chamber 8, and the braking of the hydraulic motor 2 by the negative brake 4 is reliably performed after a predetermined time has elapsed. It can realize a good stop feeling, can suppress the wear of the components of the negative brake 4, can maintain good brake performance for a long time, and can obtain high reliability. It should be noted that the first oil chamber 8 is provided before the pressure oil in the second oil chamber 12 forming the accumulator mechanism.
Of the first oil chamber 8 and the second oil chamber 1
2 is provided on the brake piston 29,
The brake piston 29 returns to the position for braking the hydraulic motor 2 after the pressure oil in the first oil chamber 8 and the pressure oil in the second oil chamber 12 are both discharged. The hydraulic motor 2 can be braked by the negative brake 4 after a predetermined time has elapsed from the stop of the oil supply.

Further, the pressure receiving area SA of the first oil chamber 8 and the second
By appropriately selecting the ratio of the pressure receiving area SB of the oil chamber 12, the braking of the hydraulic motor 2 by the negative brake 4 is realized from the above-mentioned predetermined time, that is, from when the supply of the hydraulic oil to the hydraulic motor 2 is stopped. This makes it possible to easily change the time until the braking operation of the hydraulic motor 2 with high accuracy can be realized.

In addition to the brake piston 29, the negative brake 4 including the first oil chamber 8 and the second oil chamber 12, the merging means including the relief valve 13 and the brake pipe 14, check valves 6, 16, throttle 7, etc. Since the hydraulic motor block 1 is formed integrally with the hydraulic motor 2, the size of the apparatus can be reduced and the number of parts can be reduced, and the manufacturing cost can be reduced as compared with the related art.

FIG. 4 is a hydraulic circuit diagram showing a second embodiment of the present invention, and FIG. 5 is a cross-sectional view showing a main part of the second embodiment shown in FIG.

As shown in FIG. 4, this second embodiment is also
The hydraulic motor block 40 includes a negative brake 47 for braking the rotation of the output shaft 3 of the hydraulic motor 2. The brake of the negative brake 47 is provided via the switching valve 5, the check valve 6 and the throttle 7 provided in parallel with each other. Piston 48
Is selectively connected to either the hydraulic pressure source 9 or the tank 10. First oil chamber 4
1, a check valve 6, a throttle pipe 7 communicating with a throttle 7, and a brake piston 4 of a negative brake 47.
8 and connected to a second oil chamber 43 forming an accumulator mechanism via a second check valve 44 included in the merging means. Further, a brake line 45 included in a joining means for connecting the second oil chamber 43 and the second check valve 44 is connected to the motor drain 15 via a check valve 46. Meter-in pipes 17A and 17B for motor rotation are connected to the hydraulic motor 2.

The above-described second check valve 44 is provided integrally with the brake lines 42 and 45, the check valves 6 and 46, and the throttle 7 in the hydraulic motor block 40, and is discharged from the second oil chamber 43. Only the flow of the pressure oil into the brake line 42 is permitted.

As shown in FIG. 5, the negative brake 47 comprises a fixed plate 27 whose rotation with respect to the motor casing 26 is restricted, and a rotary plate 28 which rotates integrally with the cylinder block 20 via a brake piston 48. The springs 30 can be pressed against each other by the force of the springs 30.

As shown in FIG. 5, the brake piston 4
8 and the motor casing 26 each have a cylindrical portion having three different diameters, and a first oil chamber 41 having a pressure receiving area SC and a second oil chamber 43 having a pressure receiving area SD by being fitted to each other. Is formed.

The parallel structure of the check valve 6 and the throttle 7 shown in FIG. 4 is implemented by changing the check valve poppet to a poppet 34 with a throttle having the throttle 7 as shown in FIG. The poppet 34 with the throttle is a spring 3 having a very small force.
5 energized.

The second check valve 44 shown in FIG. 4 is constituted by a ball 49 and a spring 50 having a very small force for urging the ball 49.

The check valve 46 shown in FIG.
1 and a notched retaining ring 52 for restricting the movement of the ball 51.

The operation in the second embodiment configured as described above is as follows.

At the time of starting the motor, when the hydraulic motor 2 is started, when the switching oil is supplied to the main pipe 17A (17B) and the switching valve 5 is switched to the right position in FIG.
Is supplied to the throttled poppet 34 through the switching valve 5, and the throttled poppet 34 is pushed upward and opened in FIG. 5 and supplied to the first oil chamber 41 via the brake pipe 42.

The pressure oil at this time acts on the ball 49 so as to close the ball 49.
No pressure oil is guided to the fifth and second oil chambers 43. Accordingly, the pressure oil for releasing the brake is supplied only to the first oil chamber 41, and the brake piston 48 moves upward in the figure overcoming the force of the spring 30. At this time, the ball 5 is stored in the second oil chamber 43.
The oil in the motor drain 15 is supplied through a notch provided in the retaining ring 1 and the retaining ring 52.

The force of the spring when the brake piston 48 is at the position shown in FIG. 5 is F1, the force of the spring 30 when the brake piston 48 moves upward is F2, and the first oil chamber 4
Assuming that the pressure receiving area of No. 1 is SC, the pressure of the first oil chamber 41 at the start of movement of the brake piston 48 is PC1, and the pressure at the end of movement is PC2, PC1 = F1 / SC (12) PC2 = F2 / SC (13) ).

At the time of releasing the braking, the throttle 7 does not act because the poppet 34 with the throttle moves upward in FIG.

As described above, when the braking of the hydraulic motor 2 is released when the hydraulic motor 2 is started, the braking of the hydraulic motor 2 is promptly released at the same time as the motor is started, and the motor rotation caused by the delay of the braking release at the time of starting is performed. A good motor rotation function can be obtained without causing problems such as delay, noise due to drag at the time of braking, and deterioration of the braking function due to wear of the sliding portion.

When the hydraulic motor 2 is stopped, when the supply of pressure oil to the main pipe 17A (17B) is stopped and the switching valve 5 is switched to the left position in FIG. When the supply is cut off, the force of the spring 30 causes the brake piston 48 to move downward in FIG. At this time, the oil discharged from the first oil chamber 41 is supplied to the throttled poppet 34 via the brake line 42,
The squeezed poppet 34 is moved to the original position shown in FIG. Therefore, the discharged oil is returned to the tank 10 via the throttle 7. The oil discharged from the second oil chamber 43 acts on the ball 51 so as to close the ball 51, and does not flow out to the motor drain 15. On the other hand, the ball 49 acts to open the ball 49, and the oil discharged from the second oil chamber 43 is supplied to the brake line 42.
And merges with the pressure oil discharged from the first oil chamber 41 and is discharged to the tank 10 via the throttle 7.

As described above, also in the second embodiment, after the supply of the pressure oil for braking release is stopped, the second oil chamber 43 functions as an accumulator mechanism, and the pressure oil discharged from the second oil chamber 43 and the second oil chamber 43 By joining the pressurized oil discharged from the first oil chamber 41, the amount of oil discharged through the throttle 7 is increased. As a result, it is possible to lengthen the time until the braking force is applied to the hydraulic motor 2.

As described above, after the supply of the pressure oil for braking release is stopped, the brake piston 48 moves to the lower side in FIG. 5, and the pressure oil in the second oil chamber 43 is transferred to the ball 4 via the brake line 45.
9, the ball 49 is pushed open. However, since the force of the spring 50 applied to the ball 49 is extremely weak, the pressure in the first oil chamber 41 and the brake pipe line 42 and the pressure in the second oil chamber 43 and the brake pipe It will be approximately equal to the pressure in passage 45.

The force of the spring 30 when the brake piston 48 is initially at the position shown in FIG. 5 is F1, the force of the spring 30 when the brake piston 48 moves upward is F2, and the pressure of the first oil chamber 41 is received. The area is SC, the pressure receiving area of the second oil chamber 43 is SD, and the pressure in the first oil chamber 41 and the second oil chamber 43 at the start of the movement of the brake piston 48 when shifting from the brake release state to the braking operation is P3. Assuming that the pressure in the first oil chamber 41 and the second oil chamber 43 at the original position shown in FIG. 5 at the end of the movement is P4, P3 = F2 / (SC + SD) (14) P4 = F1 / (SC + SD) (15) From equations (12) to (15), P3 = PC2 × SC / (SC + SD) (16) P4 = PC1 × SC / (SC + SD) (17)

From the equations (16) and (17), the pressures P3 and P4 acting on the throttle 7 for controlling the moving speed of the brake piston 48 during the braking operation are the pressures PC1 and PC when the braking is released.
It turns out that it is smaller than 2.

Also in the second embodiment, after the supply of the brake release hydraulic oil is stopped, the hydraulic oil discharged from the second hydraulic chamber 43 and the hydraulic oil discharged from the first hydraulic chamber 41 constitute the accumulator mechanism. And discharged through the throttle 7, the flow rate passing through the throttle 7 can be increased,
Further, the pressures of the brake pipe line 42, the first oil chamber 41, and the second oil chamber 43 acting on the throttle 7 that controls the moving speed of the brake piston 48 can be controlled to small values (throttle differential pressure reduction), The time until the braking force is applied to the motor 2 can be set long.

In the second embodiment configured as described above, the same effects as in the first embodiment can be obtained.

FIG. 6 is a hydraulic circuit diagram showing a third embodiment of the present invention, FIG. 7 is a cross-sectional view showing a main part configuration in a braking state in the third embodiment shown in FIG. 6, and FIG. It is sectional drawing which shows the principal part structure at the time of the brake release start in 3rd Embodiment shown.

As shown in FIG. 6, this third embodiment also has
A hydraulic motor block 53 includes a negative brake 54 for braking the rotation of the output shaft 3 of the hydraulic motor 2, and a throttle 64.
The first oil chamber 55 and the second oil chamber 56 provided in the brake piston 59 of the negative brake 54 are connected to the hydraulic source 9 and the tank 10 via a second switching valve 57 included in the merging means.
And the motor drain 15. The above-described second switching valve 57 is also included in the hydraulic motor block 53. The hydraulic motor 2 is connected to main pipes 17A and 17B for motor rotation.

As shown in FIGS. 7 and 8, the negative brake 54 includes a fixed plate 27 whose rotation with respect to the motor casing 58 is restricted, and a rotary plate 28 that rotates integrally with the cylinder block 20. The springs 30 can be pressed against each other by the force of the spring 30.

As shown in FIGS. 7 and 8, each of the brake piston 59 and the motor casing 58 has a cylindrical portion having three different diameters. A chamber 55 and a second oil chamber 56 having a pressure receiving area SF are formed.

As shown in FIGS. 7 and 8, the second switching valve 57 slides the spool 60, a throttle 64 provided on the spool 60, a spring 61 for urging the spool 60, and the spool 60. Pilot chamber 62 into which pressure oil to be introduced is guided
, A motor drain chamber 63, and a pre-throttle drain line 65.

The operation of the third embodiment configured as described above is as follows.

[Motor startup] When the hydraulic motor 2 is started, when the switching valve 5 is switched to the right position in FIG. 7 at the same time as supplying the pressure oil to the main pipe 17A (17B), the state shown in FIG. The pressure oil of the source 9 is supplied to the second
The spool 60 is supplied to the pilot chamber 62 of the switching valve 57, moves the spool 60 to the lower side in FIG. 8 against the force of the spring 61, and is supplied to the first oil chamber 55. At this time, the second oil chamber 5
6 is a motor drain chamber 6 through the outer periphery of the spool 60.
3 and the motor drain 15. Therefore, the pressure oil for releasing the brake is supplied only to the first oil chamber 55, and the brake piston 59 overcomes the force of the spring 30 and moves upward in FIG.

Here, the force of the spring 30 when the brake piston 59 is at the position shown in FIG. 7 is F1, and the force of the spring 30 when the brake piston 59 moves upward and the stopper 31 contacts the head end face 32. Is F2, the pressure receiving area of the first oil chamber 55 is SE, the pressure of the first oil chamber 55 at the start of the movement of the brake piston 59 is PE1, and the pressure at the end of the movement is PE2.
Then, PE1 = F1 / SE (18) PE2 = F2 / SE (19)

When the brake is released, no oil passes through the throttle 64 when the brake piston 59 moves, and therefore, the throttle 64 does not act.

As described above, as in the first and second embodiments described above, when the braking of the hydraulic motor 2 is released when the hydraulic motor 2 is started, the braking of the hydraulic motor 2 is quickly performed simultaneously with the start of the motor. A good motor rotation function can be obtained without causing problems such as a motor rotation delay caused by a brake release delay at the time of starting, a noise caused by a drag at the time of braking, and a reduction in a braking function due to wear of a sliding portion. be able to.

When the hydraulic motor 2 is stopped, if the supply of the pressure oil to the main pipe 17A (17B) is stopped when the hydraulic motor 2 is stopped, the supply of the pressure oil for releasing the brake is cut off, and the pilot chamber of the second switching valve 57 is stopped. The pressure in 62 and the first oil chamber 55 decreases, and the spool 60 moves upward by the force of the spring 61 as shown in FIG. Thus, the first oil chamber 55 and the pilot chamber 62 are shut off, and the first oil chamber 55 communicates with the pre-throttle drain pipe 65. At the same time, communication between the pre-throttle drain pipe 65 and the motor drain chamber 63 at the outer periphery of the spool 60 is cut off. Further, the force of the spring 30 causes the brake piston 59 to move downward. At this time, the pressure oil discharged from the first oil chamber 55 and the second oil chamber 56 together with the movement of the brake piston 59 merges, and flows through the drain pipe 65 before throttle, the throttle 64, and the motor drain chamber 63 through the motor drain. It is discharged to 15.

As described above, also in the third embodiment, after the supply of the release pressure oil is stopped, the second oil chamber 56 functions as an accumulator mechanism, and the pressure oil discharged from the second oil chamber 56 is used as the first oil. By joining with the pressure oil discharged from the chamber 55, the amount of oil discharged through the throttle 64 is increased. As a result, it is possible to lengthen the time until the braking force is applied to the hydraulic motor 2.

As described above, the brake piston 59 is
During the upward movement as shown in FIG. 7, the pressure in the first oil chamber 55 and the pressure in the second oil chamber 56 are equal. The pressure of the first oil chamber 55 and the second oil chamber 56 acting on the throttle 64 can be controlled to a value smaller than the pressure of the first oil chamber 55 when the braking of the hydraulic motor 2 is released. Thus, the time until the braking force is applied to the hydraulic motor 2 can be lengthened.

Also in the third embodiment, after the supply of the pressure oil for braking release is stopped, the pressure oil discharged from the second oil chamber 56 constituting the accumulator mechanism and the pressure oil discharged from the first oil chamber 55 And draining the same through the throttle 64, the amount of oil passing through the throttle 64 can be increased, and the pre-throttle drain acting on the throttle 64 that controls the moving speed of the brake piston 59. The pressure in the pipeline 65, the first oil chamber 55, and the second oil chamber 56 can be controlled to a small value (restriction differential pressure reduction), and the time until braking force is applied to the hydraulic motor 2 can be extended.

In the third embodiment configured as described above, the same effects as those in the first and second embodiments can be obtained.

[0098]

According to the present invention, the first oil chamber to which the hydraulic oil is supplied from the hydraulic power source when the hydraulic motor is released from braking is provided with an accumulator function for the brake piston of the negative brake. Since the second oil chamber is provided, it is possible to apply a braking force to the hydraulic motor after both the pressure oil in the first oil chamber and the pressure oil in the second oil chamber are discharged. After the supply of pressurized oil has been stopped, the hydraulic motor can be braked by the negative brake after a predetermined time has elapsed, ensuring a good stop feeling and suppressing the wear of the components of the negative brake. It is possible to maintain good braking performance over a long period of time and obtain high reliability.

Also, the brake piston, the first oil chamber, the second
A hydraulic motor block is provided in which a negative brake including an oil chamber and a joining means for joining the pressure oil of the first oil chamber and the pressure oil of the second oil chamber when the hydraulic motor is braked are integrated with the hydraulic motor. Therefore, it is possible to reduce the size of the device and the number of parts, and to reduce the manufacturing cost as compared with the related art.

Further, by appropriately selecting the ratio of the pressure receiving area of the first oil chamber to the pressure receiving area of the second oil chamber, the supply of the hydraulic oil to the hydraulic motor is stopped when the supply of the hydraulic oil to the hydraulic motor is stopped. The predetermined time until the braking is realized can be easily changed, and a highly accurate hydraulic motor braking operation can be realized.

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit diagram illustrating a first embodiment of a brake device for a hydraulic motor according to the present invention.

FIG. 2 is a sectional view of a main part showing a specific structure of a hydraulic motor provided in the first embodiment shown in FIG.

FIG. 3 is a cross-sectional view showing a main part configuration of the first embodiment shown in FIG.

FIG. 4 is a hydraulic circuit diagram showing a second embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a main part configuration of the second embodiment shown in FIG.

FIG. 6 is a hydraulic circuit diagram showing a third embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a configuration of a main part in a state at the time of braking in the third embodiment shown in FIG. 6;

FIG. 8 is a cross-sectional view showing a configuration of a main part at the start of braking release in the third embodiment shown in FIG.

FIG. 9 is a hydraulic circuit diagram showing a conventional brake device for a hydraulic motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydraulic motor block 2 Hydraulic motor 3 Output shaft 4 Negative brake 5 Switching valve 6 Check valve 7 Throttle 8 First oil chamber 9 Hydraulic power source 10 Tank 11 Brake line 12 Second oil chamber (accumulator mechanism) 13 Relief valve (Combining means) 14) Brake line (joining means) 15 Motor drain 16 First check valve 17A Main pipe 17B Main pipe 18 Head 20 Cylinder block 26 Motor casing 27 Fixing plate 28 Rotating plate 29 Brake piston 30 Spring 34 Poppet with throttle 35 Spring 36 Poppet 37 spring 38 poppet 39 spring 40 hydraulic motor block 41 first oil chamber 42 brake line 43 second oil chamber (accumulator mechanism) 44 second check valve (joining means) 45 brake line (joining means) 46 check valve 47 negative Live brake 48 Brake piston 49 Ball 50 Spring 51 Ball 52 Retaining ring 53 Hydraulic motor block 54 Negative brake 55 First oil chamber 56 Second oil chamber (accumulator mechanism) 57 Second switching valve (Joint means) 58 Motor casing 59 Brake piston 60 Spool 61 Spring 62 Pilot chamber 63 Motor drain chamber 64 Throttle 65 Drain line before throttling

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yoshinori Takeuchi 650, Kandachi-cho, Tsuchiura-shi, Ibaraki F-term in the Tsuchiura Works of Hitachi Construction Machinery Co., Ltd. (Reference) 2D015 BA04 3H084 AA06 AA16 AA16 BB14 BB26 BB27 CC02 CC47 CC49 CC58 CC62 3H089 CC01 CC15 DB03 DB13 DB33 DB45 DB48 DC02 FF01 GG02 HH16 JJ02 3J058 AA44 AA48 AA53 AA59 AA70 AA79 AA88 BA67 CC03 CC07 CC72 CC78 FA17

Claims (11)

[Claims] 1. A negative brake for braking a hydraulic motor, a hydraulic source for supplying pressure oil for releasing the braking of the hydraulic motor by the negative brake, and a supply and discharge of the hydraulic oil from the hydraulic source to the negative brake. A hydraulic valve brake device comprising: a switching valve to be operated; a throttle working when discharging the hydraulic oil from the negative brake; and an accumulator mechanism for discharging the hydraulic oil when the braking of the hydraulic motor is released. The brake piston portion is provided with a first oil chamber to which the pressure oil from the hydraulic source is supplied when the hydraulic motor is released from braking, and a second oil chamber that forms the accumulator mechanism. Joining means for joining the pressure oil discharged from the first oil chamber and the pressure oil discharged from the second oil chamber A hydraulic motor block comprising: a hydraulic motor block formed by integrating the negative brake including the brake piston, the first oil chamber, and the second oil chamber; Brake equipment. 2. The brake device for a hydraulic motor according to claim 1, further comprising a first check valve that allows only the inflow from the tank to the second oil chamber. 3. The brake device for a hydraulic motor according to claim 2, wherein the first check valve is provided in the hydraulic motor block. 4. The method according to claim 1, wherein the joining means operates in accordance with a pressure difference between the pressure of the second oil chamber and the pressure of the first oil chamber.
2. The brake device for a hydraulic motor according to claim 1, further comprising a relief valve that joins the pressure oil discharged from the oil chamber and the pressure oil discharged from the second oil chamber. 5. The brake device for a hydraulic motor according to claim 4, wherein said relief valve is provided in said hydraulic motor block. 6. The brake device for a hydraulic motor according to claim 1, wherein the joining means includes a second check valve that allows only the flow of the pressure oil discharged from the second oil chamber. 7. The brake device for a hydraulic motor according to claim 6, wherein the second check valve is a check valve with a spring. 8. The brake device for a hydraulic motor according to claim 6, wherein the second check valve is provided in the hydraulic motor block. 9. A switching position enabling supply of pressurized oil to the first oil chamber, and merging pressure oil discharged from the first oil chamber and pressure oil discharged from the second oil chamber. 2. A valve according to claim 1, further comprising a second switching valve having a switching position.
The hydraulic motor brake device according to claim 1. 10. The hydraulic motor brake device according to claim 9, wherein said second switching valve is provided in said hydraulic motor block. 11. The negative brake is provided to face the brake piston, a spring for biasing the brake piston, a rotating plate that rotates with rotation of an output shaft of the hydraulic motor, and the rotating plate. And a fixed plate pressed against the rotating plate with the movement of the brake piston by the spring. The brake piston has three cylindrical portions having different diameters from each other, and is formed by these cylindrical portions. The brake device for a hydraulic motor according to claim 1, wherein the first oil chamber is provided in one of the two stepped portions, and the second oil chamber is provided in the other.