WO2019058711A1

WO2019058711A1 - Hydraulic motor control device

Info

Publication number: WO2019058711A1
Application number: PCT/JP2018/025758
Authority: WO
Inventors: 祐紀阪井
Original assignee: Ｋｙｂ株式会社
Priority date: 2017-09-25
Filing date: 2018-07-06
Publication date: 2019-03-28
Also published as: JP2019060373A

Abstract

A hydraulic motor control device (100) comprises a volume switching valve (30) that controls the flow of working oil supplied to and discharged from a pair of switching actuators (20, 21) that change the volume of a piston motor (1) by driving a swash plate (2). The volume switching valve (30) includes: a first control port (31d) that is open to a housing hole (33) and through which working oil supplied to and discharged from the switching actuator (20) is guided; a second control port (31e) that is open to the housing hole (33) and through which the working oil supplied to and discharged from the switching actuator (21) is guided; and a drain port (31c) that is open to the housing hole (33) and communicates with a tank (51). The drain port (31c) is provided between the first control port (31d) and the second control port (31e) in a movement direction of a spool (40).

Description

Hydraulic motor controller

The present invention relates to a hydraulic motor control device that controls a piston motor whose displacement volume changes in accordance with the tilt angle of a swash plate.

JP2016-44690A is a hydraulic motor control device that controls a piston motor whose displacement volume changes according to the tilt angle of the swash plate, and a pair of switching actuators for changing the displacement volume of the piston motor, and switching And a volume switching valve that switches hydraulic pressure introduced to the actuator.

In the hydraulic motor control device that changes the volume of the piston motor by the pair of actuators, a passage for guiding the hydraulic fluid to the pair of actuators and a passage for discharging the hydraulic fluid are respectively formed.

As the passage through which the hydraulic fluid passes increases, the number of processing steps increases and the apparatus becomes larger. Such an increase in the number of processing steps and an increase in the size of the apparatus cause an increase in the manufacturing cost.

An object of the present invention is to reduce the manufacturing cost of a hydraulic motor control device.

According to an aspect of the present invention, there is provided a hydraulic motor control device for controlling a piston motor whose displacement volume changes in accordance with a tilt angle of a swash plate, wherein the swash plate is driven to change the volume of the piston motor. A volume switching valve is provided to control the flow of hydraulic fluid supplied to and discharged from the first actuator and the second actuator, and the volume switching valve is slidable into the valve housing, the receiving hole formed in the valve housing, and the receiving hole. A spool housed in the pilot chamber, a pilot chamber facing one end of the spool to guide the pilot pressure, an urging member urging the spool against the pilot pressure of the pilot chamber A first control port to which the hydraulic fluid to be discharged is introduced, a second control port to which the hydraulic fluid to be supplied to and discharged from the second actuator is introduced, which is open to the accommodation hole, and the accommodation hole A drain port that opens and communicates with the tank, the drain port being provided between the first control port and the second control port in the direction of movement of the spool, and depending on the position of the spool, It communicates with the control port and the second control port.

FIG. 1 is a hydraulic circuit diagram of a hydraulic motor control device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a volume switching valve of the hydraulic motor control device according to the embodiment of the present invention, and showing a state in which the position is a low speed position. FIG. 3 is a cross-sectional view showing the volume switching valve of the hydraulic motor control device according to the embodiment of the present invention, and is a view showing a state of being in a high speed position.

Hereinafter, based on an attached drawing, hydraulic motor control device 100 concerning an embodiment of the present invention is explained.

FIG. 1 is a hydraulic circuit diagram of a hydraulic motor unit 101 mounted on a working machine such as a hydraulic shovel. The hydraulic motor unit 101 controls a traveling device of a working machine (not shown).

The hydraulic motor unit 101 includes a piston motor 1 whose displacement volume changes according to the tilt angle of the swash plate 2, and a hydraulic motor control device 100 that controls the operation of the piston motor 1.

The piston motor 1 is a swash plate type hydraulic piston motor that rotates in a forward or reverse direction by hydraulic fluid (hydraulic fluid) selectively supplied to the motor ports M1 and M2. The piston motor 1 has a pair of switching

actuators

20 and 21 for switching the tilt angle of the swash plate 2, and a swash plate spring 3 for biasing the swash plate 2. The switching actuator 20 corresponds to a first actuator, and the switching actuator 21 corresponds to a second actuator.

The displacement of the piston motor 1 is maximum when the tilt angle of the swash plate 2 is maximum, and is minimum when the tilt angle of the swash plate 2 is minimum. The swash plate spring 3 biases the swash plate 2 in a direction to increase the tilt angle of the swash plate 2. The switching

actuators

20 and 21 extend in the direction to reduce the tilt angle of the swash plate 2. That is, the tilt angle of the swash plate 2 changes in accordance with the biasing force of the swash plate spring 3 and the thrust of the switching

actuators

20 and 21. The rotation of the output shaft (not shown) of the piston motor 1 is transmitted to the drive wheel of the working machine via a reduction gear or the like.

The hydraulic motor control device 100 allows the operation of the piston motor 1 while maintaining the stopped state of the piston motor 1, and switches the tilt angle of the swash plate 2 to change the displacement volume to change the piston motor 1 And a first main passage 4 and a second main passage 5 which are connected to the piston motor 1 and through which hydraulic fluid flows. Here, the displacement volume is a geometric volume that the piston motor 1 displaces per rotation.

The hydraulic motor control device 100 has a plurality of ports P1, P2, T, and Ps in communication with the outside. A pump 50 for pressurizing and supplying hydraulic oil is connected to the supply and discharge ports P1 and P2. A tank 51 storing hydraulic oil is connected to the tank port T. A pilot pressure supply source (not shown) is connected to the pilot supply / discharge port Ps. Further, the supply and discharge port P1 is connected to the motor port M1 of the piston motor 1 via the first main passage 4. The supply / discharge port P 2 is connected to the motor port M 2 of the piston motor 1 via the second main passage 5.

Between the hydraulic motor control device 100 and the pump 50, there is interposed a travel control valve 52 for switching to which supply / discharge port P1, P2 hydraulic oil supplied from the pump 50 is to be introduced. The travel control valve 52 has a forward rotation position 52A for rotating the piston motor 1 in the forward direction, a stop position 52B for stopping the piston motor 1, and a reverse rotation position 52C for rotating the piston motor 1 in the reverse direction. The position of the travel control valve 52 is switched by the operator operating the operation lever 53. By this operation, the working machine advances, reverses or stops.

Since the counter balance valve 10 can adopt a known configuration, the detailed description and the detailed illustration will be omitted.

The volume switching valve 30 is a 5-port 2-position spool valve that switches supply and discharge of hydraulic oil to the switching

actuators

20 and 21.

The volume switching valve 30 communicates with a first supply port 31 a in communication with the first main passage 4 on the motor port M 1 side through the first branch passage 6 and with the second main passage 5 on the motor port M 2 side through the second branch passage 7. A second control port 31b communicating with the tank port T through the drain passage 8; a first control port 31d communicating with the switching actuator 20 through the first switching passage 22 provided with the throttle 24; And a second control port 31 e in communication with the switching actuator 21 through the second switching passage 23 provided.

The volume switching valve 30 further includes a pilot chamber 34 in which a pilot pressure is introduced from the pilot supply and discharge port Ps, and a spring 35 as a biasing member that biases a spool 40 described later against the pilot pressure.

The pilot pressure supplied from the pilot supply / discharge port Ps to the pilot chamber 34 is the pilot pressure when the speed switching lever (not shown) that switches the traveling speed of the work machine to low speed or high speed is operated by the operator to high speed. Supplied from a source. When the control lever is at the low speed side, pilot pressure is not supplied from the pilot supply / discharge port Ps to the pilot chamber 34.

The volume switching valve 30 has a low speed position 30A as a first position and a high speed position 30B as a second position.

The biasing force of the spring 35 acts to position the volume switching valve 30 at the low speed position 30A. In the low speed position 30A, both the first control port 31d and the second control port 31e communicate with the drain port 31c. In the low speed position 30A, the communication between the first control port 31d and the first supply port 31a is shut off, and the communication between the second control port 31e and the second supply port 31b is shut off.

On the other hand, the thrust by the pilot pressure guided to the pilot chamber 34 acts so that the volume switching valve 30 is positioned at the high speed position 30B. In the high speed position 30B, the first control port 31d and the first supply port 31a communicate with each other, and the second control port 31e and the second supply port 31b communicate with each other. In the high speed position 30B, the drain port 31c is disconnected from both the first control port 31d and the second control port 31e.

Next, the operation of the volume switching valve 30 will be described.

When the work machine is traveling and the speed switching lever (not shown) is not operated to the high speed side by the operator, the pilot pressure is not guided to the pilot chamber 34. The position is held at the low speed position 30A. At this time, each switching

actuator

20, 21 communicates with the tank port T through the first switching passage 22 or the second switching passage 23, respectively. Therefore, the switching

actuators

20 and 21 contract due to the biasing force of the swash plate spring 3. When the tilt angle of the swash plate 2 is maximized by the biasing force of the swash plate spring 3, the capacity of the piston motor 1 is maximized, and the piston motor 1 operates at a low speed. As a result, the traveling speed of the working machine is low.

On the other hand, when the speed switching lever is operated to the high speed side by the operator, the pilot pressure is guided to the pilot chamber 34. When the thrust by the pilot pressure guided to the pilot chamber 34 exceeds the biasing force of the spring 35, the volume switching valve 30 is switched to the high speed position 30B. At this time, the switching actuator 20 communicates with the first main passage 4 through the first switching passage 22 and the first branch passage 6, and the switching actuator 21 communicates with the second main passage 5 through the second switching passage 23 and the second branch passage 7. It communicates. During traveling of the work machine, hydraulic fluid discharged from the pump 50 is introduced to either the first main passage 4 or the second main passage 5. For this reason, in one of the switching

actuators

20 and 21, the hydraulic fluid discharged from the pump 50 is guided through the first main passage 4 or the second main passage 5 and extends against the biasing force of the swash plate spring 3. Do. When the tilt angle of the swash plate 2 is minimized by the thrust of the switching

actuators

20 and 21, the displacement of the piston motor 1 is minimized and the piston motor 1 operates at high speed. As a result, the traveling speed of the working machine becomes high.

When the position of the volume switching valve 30 is rapidly switched, the tilt angle of the swash plate 2 is rapidly changed, and the operating speed of the piston motor 1 is rapidly changed. Such a change also affects a change in the traveling speed of the work machine, and may give the operator an impact due to a sudden change in the traveling speed. In the present embodiment, resistance is applied to the flow of hydraulic fluid entering and exiting the switching

actuators

20 and 21 by the

throttles

24 and 25 respectively provided in the first switching passage 22 and the second switching passage 23. Therefore, the contraction and extension operations of the switching

actuators

20 and 21 become slow, and the impact caused by the shift of the piston motor 1 is alleviated.

Next, with reference to FIGS. 2 and 3, the specific structure of the volume switching valve 30 will be described.

The volume switching valve 30 has a valve housing 32, an accommodation hole 33 formed in the valve housing 32, and a spool 40 slidably accommodated in the accommodation hole 33.

The valve housing 32 is used in common with the body of the hydraulic motor control device 100. Not limited to this, the valve housing 32 may be provided separately from the body of the hydraulic motor control device 100.

The housing hole 33 is a through hole whose both ends are open to the surface of the valve housing 32. The openings at both ends of the accommodation hole 33 are sealed by the first cap 37 and the second cap 38.

Each of the first supply port 31a, the second supply port 31b, the drain port 31c, the first control port 31d, and the second control port 31e is formed as an annular groove on the inner peripheral surface of the accommodation hole 33. Open to

The drain port 31c is provided so as to be located between the first control port 31d and the second control port 31e in the moving direction of the spool 40 (the axial direction of the spool 40) which is the horizontal direction in the drawing. Further, the first supply port 31a is provided on the opposite side to the drain port 31c with respect to the first control port 31d. The second supply port 31 b is provided on the opposite side to the drain port 31 c with respect to the second control port 31 e. Thus, the first supply port 31a and the second supply port 31b are provided outside the first control port 31d and the second control port 31e with the drain port 31c at the center. That is, these ports are arranged in the moving direction of the spool 40 in the order of the second supply port 31b, the second control port 31e, the drain port 31c, the first control port 31d, and the first supply port 31a from the left in the drawing. It is provided side by side to the right.

The pilot chamber 34 is partitioned between one end of the spool 40 and the first cap 37 and faces one end of the spool 40. A pilot port 34 a, which is formed as an annular groove on the inner circumferential surface of the accommodation hole 33, communicates with the pilot chamber 34. Further, a spring chamber 36 as an urging chamber for housing the spring 35 is defined between the other end of the spool 40 and the second cap 38.

The spool 40 has first, second, third and

fourth land portions

41 a, 41 b, 41 c and 41 d in sliding contact with the inner circumferential surface of the housing hole 33. The outer peripheral surface of the spool 40 is between the first land portion 41a and the second land portion 41b, between the second land portion 41b and the third land portion 41c, and between the third land portion 41c and the fourth land portion 41d. The first, second and third

annular grooves

42a, 42b and 42c are formed in an annular shape.

At the end of the spool 40 on the first cap 37 side, an abutting portion 43 that abuts on the first cap 37 is provided. The abutting portion 43 functions as a stopper that restricts the further movement of the spool 40 by abutting on the first cap 37. The contact portion 43 has a slit 43 a that is formed on an end surface facing the first cap 37 and extends in the radial direction. Further, the abutting portion 43 is formed to have an outer diameter smaller than that of the first land portion 41 a. Thereby, even in the state where the contact portion 43 and the first cap 37 are in contact with each other, the pilot pressure guided from the pilot port 34a is a step surface 43b between the contact portion 43 and the first land portion 41a. The thrust by the pilot pressure acts on the spool 40 by acting on the slit 43 a.

At the other end surface of the spool 40, an accommodation recess 44 for accommodating one end of the spring 35 is formed. The other end of the spring 35 is seated on the second cap 38. The housing recess 44 constitutes a part of the spring chamber 36.

The spool 40 is further formed with an internal passage 45 communicating the housing recess 44 with the drain port 31c. The internal passage 45 has an axial passage 45a formed at the axial center of the spool 40 and in communication with the accommodation recess 44, and a radial passage 45b communicating the axial passage 45a with the second annular groove 42b. As described later, the second annular groove 42b always communicates with the drain port 31c. Therefore, by forming the radial direction passage 45b to be in communication with the second annular groove 42b, the accommodation recess 44 can be always in communication with the drain port 31c regardless of the position of the spool 40. Thus, even if the hydraulic oil leaks into the spring chamber 36, the hydraulic oil in the spring chamber 36 can be discharged to the drain port 31c through the internal passage 45. Therefore, the pressure of the hydraulic oil in the spring chamber 36 is prevented.

In a state where the pilot pressure is not led to the pilot chamber 34, as shown in FIG. 2, the spool 40 is held in a state where the contact portion 43 is in contact with the first cap 37 by the biasing force of the spring 35. Thus, the volume switching valve 30 is in the low speed position 30A.

In this state, the communication between the first control port 31 d and the first supply port 31 a is blocked by the second land portion 41 b of the spool 40. Further, the communication between the second control port 31 e and the second supply port 31 b is blocked by the fourth land portion 41 d of the spool 40. Further, the first control port 31d communicates with the drain port 31c through the second annular groove 42b, and the second control port 31e communicates with the drain port 31c through the third annular groove 42c. As described above, in the state where the volume switching valve 30 is positioned at the low speed position 30A, both the first control port 31d and the second control port 31e communicate with one drain port 31c through the inside of the accommodation hole 33.

When the pilot pressure is introduced to the pilot chamber 34, the pilot pressure acts on the slit 43a and the step surface 43b of the spool 40. Thereby, the spool 40 moves in the left direction in the drawing against the biasing force of the spring 35 until the end abuts on the second cap 38 as shown in FIG. Thus, the volume switching valve 30 is in the high speed position 30B.

In this state, the first control port 31 d and the first supply port 31 a communicate with each other through the first annular groove 42 a of the spool 40. Further, the second control port 31 e and the second supply port 31 b communicate with each other through the third annular groove 42 c of the spool 40. Further, the communication between the first control port 31 d and the drain port 31 c is blocked by the second land portion 41 b of the spool 40. Further, the communication between the second control port 31 e and the drain port 31 c is blocked by the third land portion 41 c of the spool 40. Also in this state, the second annular groove 42b of the spool 40 faces and communicates with the drain port 31c, so the internal passage 45 communicates with the drain port 31c through the second annular groove 42b.

As described above, in the volume switching valve 30, since the drain port 31c is provided between the first control port 31d and the second control port 31e, both of the first control port 31d and the second control port 31e are accommodated. The same drain port 31 c can be communicated through the inside of the hole 33. Further, no other port is provided between the drain port 31c and the first control port 31d and between the drain port 31c and the second control port 31e, and the first supply port 31a and the second supply port 31b It is provided outside the first control port 31 d and the second control port 31 e with the drain port 31 c at the center. Therefore, it is easy to configure the first control port 31d and the second control port 31e to communicate with the drain port 31c through the inside of the accommodation hole 33 without separately forming a passage in the valve housing 32 or the spool 40. Become. Therefore, since the drain port 31c can be made common, the valve housing 32 may be provided with a single drain port 31c. The volume switching valve 30 is connected to one drain port 31c and the drain port 31c in comparison with the case where two drain ports 31c are provided in correspondence to the first control port 31d and the second control port 31e, respectively. The oil passage such as the drain passage 8 can be reduced.

According to the above embodiment, the following effects can be obtained.

In the volume switching valve 30, since the drain port 31c is provided between the first control port 31d and the second control port 31e, both of the first control port 31d and the second control port 31e pass through the inside of the accommodation hole 33. The same drain port 31c can be communicated. As described above, since the drain port 31 c for discharging the hydraulic oil of the pair of switching

actuators

20 and 21 can be made common, the oil passage in the volume switching valve 30 can be reduced. Therefore, the manufacturing cost of the hydraulic motor control device 100 can be reduced.

Hereinafter, the configuration, operation, and effects of the embodiment of the present invention will be collectively described.

The hydraulic motor control device 100 that controls the piston motor 1 whose displacement volume changes according to the tilt angle of the swash plate 2 drives the swash plate 2 to change the volume of the piston motor 1, a pair of switching

actuators

20, 21 includes a volume switching valve 30 for controlling the flow of hydraulic fluid supplied to and discharged from the housing 21. The volume switching valve 30 can slide in the valve housing 32, the receiving hole 33 formed in the valve housing 32, and the receiving hole 33 And a spring 34 for urging the spool 40 against the pilot pressure of the pilot chamber 34, and an accommodation hole 33. The first control port 31 d to which the hydraulic oil supplied and discharged to the switching actuator 20 is introduced and the accommodation hole 33 are opened to supply the switching actuator 21. The second control port 31e to which the hydraulic fluid to be introduced is introduced, and the drain port 31c opened in the accommodation hole 33 and in communication with the tank 51. The drain port 31c is the first control port 31d in the moving direction of the spool 40. And the second control port 31e, and communicate with the first control port 31d and the second control port 31e through the accommodation hole 33 according to the position of the spool 40.

In this configuration, the drain port 31c is disposed between the first control port 31d and the second control port 31e, and depending on the position of the spool 40, the drain port 31c is connected to the first control port 31d and the second control port 31e through the accommodation hole 33. It communicates. As a result, the hydraulic oil of both the first control port 31 d and the second control port 31 e can be guided to the drain port 31 c without separately forming a passage in the spool 40 or the valve housing 32. Therefore, the drain port 31c can be made common, and the passage in the hydraulic motor control device 100 can be reduced. Therefore, the manufacturing cost of the hydraulic motor control device 100 can be reduced.

Further, the hydraulic motor control device 100 further includes a first main passage 4 and a second main passage 5 which are connected to the piston motor 1 and to which the hydraulic oil supplied to and discharged from the piston motor 1 is introduced. And a first supply port 31a communicating with the first main passage 4 and opening in the accommodation hole 33, and a second supply port 31b communicating with the second main passage 5 and opening in the accommodation hole 33; The first supply port 31a is provided on the side opposite to the drain port 31c with respect to the first control port 31d, and the second supply port 31b is provided on the side opposite to the drain port 31c with respect to the second control port 31e. Be

Further, in the hydraulic motor control device 100, the volume switching valve 30 sets the low speed position 30A in a state where the pilot pressure is not led to the pilot chamber 34 and the high speed position 30B in a state where the pilot pressure is led to the pilot chamber 34. In the low speed position 30A, the communication between the first control port 31d and the first supply port 31a is shut off, and the communication between the second control port 31e and the second supply port 31b is shut off, so that the high speed position is achieved. In 30B, the first control port 31d and the first supply port 31a communicate with each other, and the second control port 31e and the second supply port 31b communicate with each other, and the drain port 31c is in the first control port in the low speed position 30A. It communicates with both 31d and the second control port 31e, and in the high speed position 30B, the first control Both the communication over preparative 31d and the second control port 31e is cut off.

The hydraulic motor control device 100 further includes a spring chamber 36 facing the other end of the spool 40 and housing a spring 35, and the spool 40 has an internal passage 45 which constantly communicates the spring chamber 36 and the drain port 31c. Provided.

In this configuration, since the hydraulic oil of the spring chamber 36 can be discharged to the drain port 31 c, it is possible to prevent the spring chamber 36 from being pressed.

As mentioned above, although the embodiment of the present invention was described, the above-mentioned embodiment showed only one of the example of application of the present invention, and in the meaning of limiting the technical scope of the present invention to the concrete composition of the above-mentioned embodiment. Absent.

For example, the hydraulic motor control device 100 according to the embodiment of the present invention is also applicable to control of a turning device that turns a cab of a digging device or a construction machine. Moreover, you may apply not only to a construction machine but to the rotation drive provided in an agricultural machine or a ship. In these devices, when the operator operates the control lever, the devices rotate forward, reverse or stop.

Further, in the present embodiment, the hydraulic oil is used as the hydraulic fluid, but instead, a hydraulic fluid such as a water-soluble alternative liquid may be used, for example.

The present application claims priority based on Japanese Patent Application No. 2017-184192 filed on September 25, 2017, to the Japan Patent Office, and the entire contents of this application are incorporated herein by reference.

Claims

In a hydraulic motor control device for controlling a piston motor whose displacement volume changes in accordance with the tilt angle of a swash plate,
It has a volume switching valve that controls the flow of hydraulic fluid supplied to and discharged from a first actuator that drives the swash plate to change the volume of the piston motor, and
The volume switching valve is
A valve housing,
A receiving hole formed in the valve housing;
A spool slidably received in the receiving hole;
A pilot chamber in which a pilot pressure is introduced at one end of the spool;
A biasing member for biasing the spool against the pilot pressure in the pilot chamber;
A first control port which is opened in the housing hole and into which the hydraulic fluid supplied to and discharged from the first actuator is introduced;
A second control port which is opened to the receiving hole and into which the hydraulic fluid supplied to the second actuator is introduced;
And a drain port opened in the receiving hole and in communication with the tank;
The drain port is provided between the first control port and the second control port in the moving direction of the spool, and the first control port and the second control through the receiving hole according to the position of the spool. Hydraulic motor controller communicating with the port.
The hydraulic motor control device according to claim 1, wherein
It further comprises a first main passage and a second main passage which are connected to the piston motor and to which hydraulic fluid supplied to and discharged from the piston motor is introduced.
The volume switching valve is
A first supply port in communication with the first main passage and opening in the accommodation hole;
And a second supply port communicating with the second main passage and opening in the accommodation hole.
The first supply port is provided opposite to the drain port with respect to the first control port,
The hydraulic motor control device according to claim 1, wherein the second supply port is provided on the side opposite to the drain port with respect to the second control port.
The hydraulic motor control device according to claim 2, wherein
The volume switching valve has a first position where the pilot pressure is not led to the pilot chamber, and a second position where the pilot pressure is led to the pilot chamber,
In the first position, the communication between the first control port and the first supply port is cut off, and the communication between the second control port and the second supply port is cut off,
In the second position, the first control port and the first supply port communicate with each other, and the second control port and the second supply port communicate with each other,
The drain port communicates with both the first control port and the second control port in the first position, and communicates with both the first control port and the second control port in the second position. Hydraulic motor control unit shut off.
The hydraulic motor control device according to claim 1, wherein
The apparatus further comprises an urging chamber facing the other end of the spool and accommodating the urging member,
The hydraulic motor control device according to claim 1, wherein the spool is provided with an internal passage for constantly communicating the biasing chamber and the drain port.