JPH10181690A - Hydraulic drive system for fishing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic drive system for a fishing device in which oil can be supplied in accordance with load of a fishing device, and in which drag torque can be reduced without requiring a shuttle valve, pilot pipings, etc., in a hydraulic drive system without requiring a clutch. SOLUTION: A system is composed of a swash plate piston pump 4, a motor 2 to actuate the swash plate piston pump 4, a discharge pressure constant type regulator 20 to actuation-control a servo piston 49, and fishing devices 8, 10, 12 to perform fishing work. In this case, the regulator 20 is composed in such a way that the oil pressure fed from the swash plate piston pump 4 can be set at high and low, and the oil pressure is set at low by use of a second relief valve 98 when the fishing devices 8, 10, 12 are nonactuating, while it is set high by a first relief valve 88 when the fishing devices 8, 10, 12 are actuating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic drive system for a fishing device which operates the fishing device with pressure oil.

[0002]

2. Description of the Related Art Fishing boats are equipped with fishing equipment for winding up fishing nets. The fishing apparatus is generally operated by a hydraulic drive system driven by a motor of a fishing boat. As a hydraulic drive system for operating a fishing device, for example, there is one disclosed in Japanese Patent Application Laid-Open No. Hei 6-344991. This known hydraulic drive system includes a variable displacement hydraulic pump operated by a prime mover, and a plurality of fishing devices driven by oil supplied from the hydraulic pump. The plurality of fishing devices are arranged in parallel with the variable displacement hydraulic pump, and by switching the operation valve of each fishing device, oil from the hydraulic pump is supplied to the corresponding fishing device. In this hydraulic drive system, there is no clutch between the prime mover and the hydraulic pump for connecting and disconnecting power transmission, and therefore, the configuration of the hydraulic drive system is simplified.

Generally, in a system without a clutch, when the load is small, that is, when the fishing device is not used, it is necessary to reduce the entrained torque of the hydraulic pump (loss of torque consumed when the hydraulic pump is not used). Therefore, the above-mentioned known hydraulic drive system is configured as follows. A load sensing type regulator is provided in connection with the variable displacement hydraulic pump, and a shuttle valve, a pilot pipe, etc. for detecting the load of each fishing device are provided, and the maximum load pressure of a plurality of fishing devices is adjusted to the regulator. It is configured to be fed back. Therefore, when the fishing devices are operating, the maximum load pressures of the plurality of fishing devices are fed back to the regulator, and oil having a pressure and a flow rate corresponding to the maximum load pressure is supplied from the variable displacement hydraulic pump to each fishing device. On the other hand, when the fishing apparatus is not operating, the load pressure is substantially zero (zero), so that the pressure of the oil supplied from the hydraulic pump is significantly reduced, whereby the rotating torque of the hydraulic pump is reduced. Reduced.

[0004]

However, in the above-mentioned hydraulic drive system of the fishing apparatus, a shuttle valve, a pilot pipe, and the like are required in order to detect the maximum load pressure of the fishing apparatus. It must be added to the drive system, which makes the examination of piping arrangement and piping work complicated, and increases the cost for the equipment.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a hydraulic drive system which does not require a clutch, which can supply oil according to the load of a fishing apparatus without the need for a shuttle valve, a pilot pipe and the like. An object of the present invention is to provide a hydraulic drive system for a fishing device that can reduce torque.

[0006]

SUMMARY OF THE INVENTION The present invention controls a cylinder block in which a cylinder is defined, a piston slidably mounted on the cylinder block, a swash plate to which one end of the piston is connected, and a tilt angle of the swash plate. A swash plate piston pump having a servo piston for carrying out, a prime mover directly connected to the swash plate piston pump without using a clutch means,
A constant discharge pressure regulator for controlling the operation of the servo piston, an oil tank containing oil, and a fishing device for performing fishing work are provided.The oil tank and the swash plate piston pump are connected via an oil supply passage. The swash plate piston pump and the fishing device are connected via an oil supply flow path, the fishing device and the oil tank are connected via an oil return flow path, and the constant discharge pressure regulator has a set pressure. Can be set to a low pressure value and a high pressure value larger than the low pressure value.When the set pressure of the constant discharge pressure type regulator is a low pressure value, the swash plate piston pump sends the oil to the oil supply passage. The pressure of the supplied oil is set to be low corresponding to the low pressure value, and when the set pressure of the constant discharge pressure regulator is a high pressure value, the oil is supplied from the swash plate piston pump to the oil supply passage. Oil pressure is high pressure value Is set high in response, it is a hydraulic drive system of the fishing device according to claim. According to the present invention, since the swash plate piston pump is used as a hydraulic pump for supplying oil to the fishing device, the required amount of oil is supplied to the fishing device by adjusting the inclination angle of the swash plate. be able to. In addition, a constant discharge pressure type regulator is provided in association with the swash plate piston pump, and this regulator can set the pressure of the oil supplied from the swash plate piston pump to a low pressure and a high pressure. When the fishing device is inactive, the set pressure of the regulator is set to a low pressure value. At this time, the pressure of the oil supplied from the swash plate piston pump is set to a low pressure, and when the fishing device is not operated, the inclination angle of the swash plate is reduced, and the discharge amount from the swash plate piston pump is almost zero. (Zero), so that the rotating torque of the swash plate piston pump is reduced. When the fishing apparatus operates, the set pressure of the regulator is set to a high pressure value. At this time, the pressure of the oil supplied from the swash plate piston pump is set to a high pressure, whereby sufficient pressure oil is supplied to the fishing apparatus.

Further, according to the present invention, in the constant discharge pressure regulator, the first pressure setting means for setting the set pressure to a high pressure value and the second pressure setting means for setting the set pressure to a low pressure value.
A main relief valve for preventing the pressure of the oil flowing therethrough from abnormally increasing, and a pressure switching port of the main relief valve. Is configured such that the set pressures of the first and second pressure setting means act on it, and when the set pressure of the constant discharge pressure regulator is set to a high pressure value by the first pressure setting means, The high pressure value set by the first pressure setting means acts on the pressure switching port of the main relief valve, whereby the relief pressure of the main relief valve is set to a high pressure, while the set pressure of the constant discharge pressure regulator is reduced. When the low pressure value is set by the second pressure setting means, the low pressure value set by the second pressure setting means acts on the pressure switching port of the main relief valve. Wherein the relief pressure of the valve is set to a low pressure. According to the present invention, the main relief valve is disposed in the oil supply passage through which oil is supplied from the swash plate piston pump, and the first and second pressures are connected to the pressure switching ports of the main relief valve. The pressure set by the setting means acts. That is, when the high pressure value is set by the first pressure setting means, the high pressure value by the first pressure setting means acts on the pressure switching port of the main relief valve, so that the relief pressure of the main relief valve is reduced. A high pressure corresponding to the high pressure value is set. On the other hand, when the low pressure value is set by the second pressure setting means, the low pressure value by the second pressure setting means acts on the pressure switching port of the main relief valve. A low pressure corresponding to the low pressure value is set.

[0008]

FIG. 1 is a hydraulic circuit diagram schematically showing one embodiment of a hydraulic drive system for a fishing device according to the present invention. FIG. 2 is a sectional view showing the swash plate piston pump in the hydraulic drive system of FIG.

In FIG. 1, an illustrated hydraulic drive system includes an internal combustion engine 2 (constituting a motor) mounted on a fishing boat.
The swash plate piston pump 4 operated by the internal combustion engine 2 is directly connected to the swash plate piston pump 4. Directly connected means that the swash plate piston pump 4
Means that the swash plate piston pump 4 is rotationally driven when the internal combustion engine 2 is rotated. The hydraulic drive system also includes an oil tank 6 in which oil such as oil is stored, and fishing devices 8, 10 and 12 that are operated by oil from a swash plate piston pump 4. In the present embodiment, a fishing boat (not shown) is equipped with three fishing devices 8, 10, and 12 for winding up fishing nets. Each of the fishing devices 8, 10, 12 has substantially the same configuration, and includes fishing device main bodies 8a, 10a, 12 including a hydraulic motor (not shown).
The fishing device main bodies 8a, 10a, and 12a are provided with switching valves 8b, 10b, and 12b for regulating the supply amount of the oil supplied thereto and switching the supply direction. The switching valves 8b, 10b, and 12b are provided with switching levers 8c, 10c, and 12c, respectively. By operating the switching levers 8c, 10c, and 12c, the switching valves 8b, 10b, and 12b are set to the non-operation position and the first position. The switching levers 8c, 10c, and 12c are selectively positioned in the operating position and the second operating position, and the amount of oil supplied through the switching levers 8c, 10c, and 12c can be adjusted according to the operating angle.

The switching valves 8b, 10b, 12b and the swash plate piston pump 4 are connected in parallel via an oil supply passage 14, and the switching valves 8b, 10b, 12b and the oil tank 6 are connected to an oil return. They are connected in parallel via a flow path 16.
In addition, the switching valves 8b, 10b, 12b and the fishing device body 8
a, 10a and 12a are the oil flow paths 8d and 10a, respectively.
d, 12d and oil flow paths 8e, 10e, 12e. With this configuration, in the first operating position where the switching valve 8a (or 10a, 12a) is switched to the right in FIG.
4 and the oil flow path 8d (or 10d, 12d), and the oil return flow path 16 and the oil flow path 8e (or 10d).
e, 12e), and the oil from the swash plate piston pump 4 receives the oil from the oil supply passage 14 and the oil passage 8d (or 10d, 1d).
2d), fishing equipment body 8a (or 10a, 12a),
The oil flows through the oil flow path 8e (or 10e, 12e) and the oil return flow path 16, and thereby the fishing device 8 (or 1e).
0, 12) is driven to rotate in a predetermined direction (for example, a fishing net is wound up). On the other hand, in the second operation position where the switching valve 8a (or 10a, 12a) is switched to the left in FIG. 1, the oil supply passage 14 and the oil passage 8e (or 10e, 12e) are communicated with each other. The oil return flow path 16 is communicated with the oil flow path 8d (or 10d, 12d), and the oil from the swash plate piston pump 4 receives the oil from the oil supply flow path 14 and the oil flow path 8e (or 1d).
0e, 12e), fishing equipment body 8a (or 10a, 1
2a), flowing through the oil flow passage 8d (or 10d, 12d) and the oil return flow passage 16, whereby the fishing equipment 8
A (or 10, 12) pressure oil motor (not shown) is rotationally driven in a direction opposite to a predetermined direction (for example, a fishing net is released). In the present embodiment, since the oil supply passage 14 and the oil return passage 16 are connected in parallel to the fishing devices 8, 10, 12, the fishing device 8 in which the switching valves 8b, 10b, 12b are switched. , Swash plate piston pump 4
Fishing equipment 8,1 to which oil is fed from
0,12 is activated. In this example, three fishing devices 8, 10, and 12 are provided, but the present invention can also be applied to a device equipped with one, two, or four or more fishing devices.

A constant discharge pressure regulator 20 is provided in connection with the swash plate piston pump 4.
By the action of 0, the pressure of the oil supplied from the swash plate piston pump 4 is switched to a low pressure, a high pressure, and an intermediate pressure therebetween. First, the configuration of the swash plate piston pump 4 will be briefly described with reference to FIG. In FIG. 2, the illustrated swash plate piston pump 4 includes a housing 21, and a front cover 22 is mounted on a front surface of the housing 21.
A rear cover 24 is mounted on the rear surface. A rotating shaft 30 is rotatably supported by the front cover 22 and the rear cover 24 via bearings 26 and 28. This rotating shaft 30
Is connected directly to the output shaft of the internal combustion engine 2. Housing 2
A cylinder block 32 that rotates integrally with the rotation shaft 30 is provided in the cylinder block 1. In the cylinder block 32,
A plurality of cylinders 34 are defined at substantially equal intervals in the circumferential direction, and a piston 36 is slidably disposed in each cylinder 34. One end of the cylinder 34 is rotatably connected to a shoe member 38 in an arbitrary direction, and the shoe member 38 is slidably supported by a swash plate 40. As shown in FIG. 2, the swash plate 40 is arranged to be inclined at a predetermined angle with respect to the axis of the rotating shaft 30, whereby the cylinder 34 is
Insertion and protrusion of the piston 36 into the inside are allowed. A swash plate support member 42 is fixed to the inner surface of the front cover 22, and a hemispherical protrusion 44 of the swash plate 40 is slidably received on a hemispheric inner surface 44 of the swash plate support member 42. One end of a connecting member 48 is rotatably connected to one end of the swash plate 40, and the other end of the connecting member 48 is connected to a servo piston 49. A small piston portion 50 having a small outer diameter is provided at one end of the servo piston 49, and the small piston portion 50 is slidably accommodated in a small pressure chamber 51 having a relatively small sectional area. A large piston portion 52 having a large outer diameter is provided at the other end of the servo piston 49.
Are slidably accommodated in a large pressure chamber 53 having a relatively large sectional area. In such a servo piston 49, the small piston portion 50 is set to have a relatively small pressure receiving area, and the large piston portion 52 is set to have a relatively large pressure receiving area. Oil from the regulator 20 acts.

A valve plate 54 is fixed to the inner surface of the rear cover 24, and an oil suction port 56 and an oil discharge port 58 are formed in the valve plate 54. The oil suction port 56 is communicated with an oil suction channel 60 formed in the rear cover 24.
The oil supply passage 64 (FIG. 1) communicates the oil tank 6 with the swash plate piston pump 4. Also, the oil discharge port 5
Numeral 8 communicates with an oil discharge passage 62 formed in the rear cover 24, and the oil discharge passage 62 communicates with the oil supply passage 14 (FIG. 1).

With this configuration, when the rotating shaft 30 is driven to rotate in a predetermined direction by the rotation of the internal combustion engine 2,
Together with this, the cylinder block 32, the piston 36 and the shoe member 38 are rotated. When rotated, the swash plate 40 is inclined with respect to the axis of the rotating shaft 30.
When the piston 36 is located at the upper end position in FIG. 2 (the upper position in FIG. 2), the piston 36 is at the position where it is most inserted into the cylinder 34, while the piston 3
6 is the lower end position in FIG. 2 (the lower position in FIG. 2)
Is located at the position where the piston 36 projects most from the inside of the cylinder 34. Therefore, while the rotating shaft 30 rotates in a predetermined direction and the piston 36 moves from the upper end position to the lower end position, for example, the piston 36 moves in a direction to protrude from the cylinder 34, whereby the oil from the oil supply passage 64 Is sucked into the cylinder 34 through the oil suction port 56. On the other hand, while the piston 36 moves from the lower end position to the upper end position, the piston 36 moves in a direction in which the piston 36 is inserted into the cylinder 34, whereby oil in the cylinder 34 is sent to the oil supply passage 14 through the oil discharge port 58. Be paid.

When the inclination angle of the swash plate 40 is small, the piston 3 with respect to the cylinder 34 is easily understood.
6 is small, and therefore the swash plate piston pump 4
Oil supply is reduced. When the inclination angle of the swash plate 40 increases, the amount of movement of the piston 36 with respect to the cylinder 34 increases, and therefore, the oil supply amount of the swash plate piston pump 4 increases. The inclination of the swash plate 40 is adjusted by the oil pressure acting on the small piston portion 50 and the large piston portion 52 of the servo piston 49. When the piston 49 moves rightward in FIG. However, when the piston 49 moves to the left in FIG. 2, the inclination angle of the swash plate 40 decreases.

Referring again to FIG. 1, the discharge pressure constant type shown in FIG.
The regulator 20 includes a spool valve 70 and a flow path switching valve 72.
It has. In the present embodiment, the spool valve 70
The first acting to move the valve body to the right in FIG.
Move the pilot port and valve body to the left in FIG.
A second pilot port operative to actuate
ing. The spool valve 70 also includes a first and a second
The first port is connected to an oil flow path 76.
The oil passage 76 is connected to the oil supply passage 14.
You. The second port of the spool valve 70 is
To the oil tank 6, the third port of which is connected to the oil passage 7
9 to the large pressure chamber 53 of the servo piston 49
Have been. The oil passage 76 is connected to a spool valve via an oil passage 78.
70 connected to the first pilot port
And a small pressure chamber of the servo piston 49 through the oil passage 80.
51. Also, from the oil flow path 76 to the oil flow path 8
4 branches. In the oil flow path 84, a throttle member 86 and
And first relief valve 88 (constituting first pressure setting means).
Are arranged. The throttle member 86 is connected to the oil passage 76
The flow rate of the oil supplied to the oil flow path 84 is restricted. First
The setting relief valve 88 is fed through the oil flow path 84
Oil pressure value is, for example, 205 kg / cm^Two About high pressure
The oil pressure value of the oil flow path 84 is set to 2
05kg / cm Is exceeded, the first relief valve 88 opens.
Oil flow from the oil supply passage 14 through the oil passage 76
Excess oil supplied to the passage 84 is passed through an oil passage 90 to an oil tank.
Returned to link 6.

A portion of the oil passage 84 between the throttle valve 86 and the first relief valve 88 is connected to a second pilot port of the spool valve 70 via an oil passage 92. The spool valve 70 is also provided with a pilot spring 91 for biasing the valve body to the left in FIG. 1, and the set pressure of the pilot spring 91 is, for example, 5
It can be set to about kg / cm ² . The oil flow path 79 and the oil flow path 84 are connected via an oil flow path 120, and a throttle member 87 is provided in the oil flow path 120.

With this configuration, when the spool valve 70 is at the first operating position shown in FIG. 1, the oil flow path 79 and the oil flow path 77 are communicated, and the servo piston 4
The oil in the large pressure chamber 53 is returned to the oil tank 6. When the spool valve 70 moves to the right in FIG. 1 and is in the neutral position, the oil passage 79 and the oil passage 76 or the oil passage 77
And the supply and discharge of oil to and from the high-pressure chamber 53 are stopped. When the spool valve 70 is further moved rightward in FIG. 1 and is in the second operating position, the oil flow path 76 and the oil flow path 79 are in communication, and the oil from the oil supply flow path 14 is large. The pressure is supplied to the pressure chamber 53.

An oil passage 96 is provided bypassing the first relief valve 88, and the oil passage 96 has a passage switching valve 72.
And a second relief valve 98 (constituting second pressure setting means). In the present embodiment, the flow path switching valve 72 is in one of the non-operating position shown in FIG. 1, the first operating position moving upward in FIG. 1, and the second operating position moving downward in FIG. Selectively positioned. The first port of the flow path switching valve 72 has an oil flow path 9.
6 is connected to the second port thereof, and an oil flow path 100 communicating with a portion of the oil flow path 84 downstream of the first relief valve 88 is connected to the second port. A second relief valve 98 is disposed in a portion of the oil flow passage 96 between a connection portion with the oil flow passage 100 and a portion where the flow path switching valve 72 is provided. The second relief valve 98 sets the pressure value of the oil supplied to the oil flow path 96 when the flow path switching valve 72 is at the first operating position to a low pressure value of, for example, about 15 kg / cm ^2. . If the pressure value of the oil in the oil passage 96 exceeds 15 kg / cm ² when the passage switching valve 72 is in the first operating position, the second relief valve 98 is opened, and the oil passages 76 and 84 are opened.
Excess oil supplied to oil passage 96 through oil passage 90
To the oil tank 6.

A third relief valve 102 is provided in parallel with the second relief valve 98. In the embodiment, the oil flow path 104 is provided so as to bypass a part of the oil flow path 96, and the third relief valve 102 is provided in the oil flow path 104. The oil passage 96 is connected to a third port of the passage switching valve 72, and the oil passage 104 is connected to a fourth port of the passage switching valve 72. Third relief valve 102
Sets the pressure value of the oil supplied to the oil flow path 104 when the flow path switching valve 72 is at the second operating position to, for example, 135 kg /
Set to a medium pressure value of about cm ² . If the pressure value of the oil in the oil flow path 104 exceeds 135 kg / cm ² when the flow path switching valve 72 is in the second operating position, the third relief valve 10
2 is opened, and the excess oil supplied to the oil flow path 104 through the oil flow paths 76, 86, 96 is returned to the oil tank 6 through the oil flow path 90.

When in the inoperative position, the flow path switching valve 72 shuts off the communication between the oil flow path 96 and the oil flow paths 96 and 104, and the communication between the oil flow path 100 and the oil flow paths 96 and 104. However, when it moves upward in FIG. 1 and is positioned at the first operating position, it communicates with the oil flow path 96, and when it moves downward and is positioned at the second operating position in FIG. The passage 96 communicates with the oil passage 104, and the oil passage 100 communicates with the oil passage 96.

A relief flow passage 106 connected to the oil tank 6 is connected to the oil supply flow passage 14, and a main relief valve 108 is disposed in the relief flow passage 106. The main relief valve 108 includes a pressure switching port and a pilot spring 11.
0, and the pressure switching port is connected to the connection portion of the oil flow paths 84, 96, and thus the pressure switching port has the first, second and third relief valves 88, 98, 1
The set pressure set by 02 acts. The set pressure of the pilot spring 110 of the main relief valve 108 can be set to, for example, about 10 kg / cm ² . With this configuration, the first
When the pressure set by the relief valve 88 is set, the set pressure of the first relief valve 88, that is, 205 kg / cm ² acts on the pressure switching port of the main relief valve 108, thereby The set pressure of the valve 108 is set to a relief pressure obtained by adding the pressure of the pilot spring 110 to that value. When the pressure of the oil flowing through the oil supply passage 14 exceeds 215 kg / cm ² , the main relief valve 108 is opened. Becomes When the pressure set by the second relief valve 98 is set in the regulator 20, the set pressure of the second relief valve 98, that is, 15 kg / cm ² is set to the main relief valve 1.
08, which causes the set pressure of the main relief valve 108 to reach its value
0, that is, 25 kg / cm ^2, and the pressure of the oil flowing through the oil supply passage 14 is 25
When the pressure exceeds kg / cm ² , the main relief valve 108 is opened. Further, when the set pressure set by the third relief valve 102 is set in the regulator 20, the set pressure of the third relief valve 104, that is, 135 kg / cm ² is supplied to the pressure switching port of the main relief valve 108. This causes the set pressure of the main relief valve 108 to be set to the value obtained by adding the pressure of the pilot spring 110 to that value, that is, 145 kg / cm ^2, and the pressure of the oil flowing through the oil supply passage 14 to be 145 kg / cm ² cm ²
Is exceeded, the main relief valve 108 is opened.

Next, the operation of the above-described hydraulic drive system
Will be described. Referring mainly to FIG.
When 8, 10, 12 are not operating (fishing equipment 8, 10, 1
2 switching valves 8b, 10b and 12b are held in the non-operation position.
), The flow path switching valve 72 is in the first operating position.
It is positioned in. In this state, the flow path switching valve 7
The oil flow path 96 is in communication with the
The path 100 and the oil flow path 104 are communicated. Therefore,
The pressure of the oil flowing through the oil passage 96 is 15 kg / cm. Cross over
The oil was supplied from the oil supply passage 14 to the oil passages 76 and 96.
The oil is returned to the oil tank 6 through the second relief valve 98.
Therefore, the oil supply flow path 1
The pressure of the oil supplied to the fourth relief valve 98 is controlled by the second relief valve 98.
Is set to a pressure corresponding to the pressure set as described above. this
At this time, the pressure of the oil flowing through the oil supply passage 14 is
Small pressure chamber 51 of servo piston 49 through 6, 80
The first of the spool valve 70 via the oil passages 76 and 78
Spool to pilot port and via oil flow path 76
Acts on the first port of the valve 70 but restricts the oil flow path 84
Due to the presence of the valve 86, the second pyro of the spool valve 70
The outlet port is set by a second relief valve 98.
Pressure, ie 15 kg / cm^Two Works. But
As a result, the amount of oil flowing through the oil supply passage 14 increases,
The pressure acting on the second pilot port and the pilot
When the pressure of the spring 91 becomes greater than the combined pressure,
The valve body of the valve 70 moves to the right, and the oil flow path 76 and the oil flow path
79 is communicated, and the oil from the oil supply passage 14 is
The large pressure chamber 53 of the ton 49 is fed. Therefore, high pressure
The pressure in the power chamber 53 increases, and the servo piston 49 moves to the position shown in FIG.
The swash plate 40 (FIG. 2).
The inclination angle of the swash plate piston pump
The oil supply from the pump 4 is reduced, and
Also decrease. On the other hand, the amount of oil flowing through the oil supply passage 14 decreases.
The pressure acting on the second pilot port
It becomes smaller than the composite pressure of the pressure of the pilot spring 91.
Then, the valve body of the spool valve 70 moves to the left, and the oil passage 79
And the oil passage 77 are communicated with each other, and the oil in the large pressure chamber 53 is stored in the oil tank.
Returned to 6. Therefore, the pressure in the large pressure chamber 53 decreases.
The servo piston 49 is moved rightward in FIG.
This increases the inclination angle of the swash plate 40 (FIG. 2).
As a result, oil is supplied from the swash plate piston pump 4.
As the volume increases, the discharge pressure also increases. Like this
The swash plate piston pump 4
The pressure of the supplied oil is the set pressure of the second relief valve 98.
The sum of the force and the set pressure of the pilot spring of the spool valve 70,
That is, 20 kg / cm^Two This pressure is set to a low pressure
Power pressure oil is sent to fishing equipment 8,10,12
You. At this time, it is set by the second relief valve 98.
The hydraulic pressure of the low pressure value is applied to the pressure switching port of the main relief valve 108.
The relief pressure is lower than the above low pressure value.
The corresponding pressure, ie 25 kg / cm^Two Set to oil
The pressure of the oil fed through the feed channel 14 is 25 kg /
cm^Two Is exceeded, the main relief valve 108 opens.
Prevents abnormally high pressure, and blows the oil to the oil tank
Returned to 6. As described above, the fishing devices 8, 1
When 0 and 12 are not operated, the swash plate piston pump 4
The pressure of the oil supplied from the swash plate 4 is low.
It is controlled with a tilt angle of 0, so
The torque is reduced and the torque loss is reduced.

The fishing devices 8, 10, 12 are in the operating state (the switching valves 8b, 10b, 12b of the fishing devices 8, 10, 12 are held in the first operating position or the second operating position). In a medium load state where the load is medium, the flow path switching valve 72 is positioned at the second operating position. In this state, the oil flow path 96 and the oil flow path 104 are communicated via the flow path switching valve 72, and the oil flow path 100 and the oil flow path 96 are communicated. Is supplied to the oil flow path 104 through the oil flow paths 76 and 96. Therefore, the oil pressure in the oil flow path 104 becomes 135
When the pressure exceeds kg / cm ² , the oil supply flow path 14
6, 96 is returned to the oil tank 6 through the third relief valve 102, so that the pressure of the oil supplied from the swash plate piston pump 4 to the oil supply passage 14 is The pressure is set to a pressure corresponding to the pressure set by the third relief valve 102. At this time, the pressure of the oil flowing through the oil supply passage 14 is set to the servo piston 49 in the same manner as described above.
Act on the first pilot port of the spool valve 70 and the first port of the spool valve 70, while the second pilot port of the spool valve 70
The pressure set by the relief valve 102, ie, 135 kg / cm ² acts. Therefore, the oil supply amount flowing through the oil supply passage 14 increases, and the pressure is applied to the pressure acting on the second pilot port and the pilot spring 91.
When the pressure becomes larger than the combined pressure of the pressures, the valve body of the spool 70 moves to the right, the oil flow path 76 and the oil flow path 79 communicate with each other, and the oil from the oil supply flow path 14 It is sent to the large pressure chamber 53. Therefore, the servo piston 49 is moved to the left in FIG. 1, whereby the inclination angle of the swash plate 40 (FIG. 2) is reduced, and the amount of oil supplied from the swash plate piston pump 4 is reduced. The discharge pressure also drops. On the other hand, when the supply amount of the oil flowing through the oil supply passage 14 decreases and the pressure becomes smaller than the combined pressure of the pressure acting on the second pilot port and the pressure of the pilot spring 91, the valve of the spool valve 70 The body moves to the left, and the oil flow path 79 and the oil flow path 77 communicate with each other.
3 is returned to the oil tank 6. Therefore, the servo piston 49 is moved rightward in FIG. 1, thereby increasing the inclination angle of the swash plate 40 (FIG. 2) and increasing the oil supply from the swash plate piston pump 4. The discharge pressure also increases. Since the spool valve 70 operates as described above, the pressure of the oil supplied from the swash plate piston pump 4 is set to, for example, a medium pressure of 140 kg / cm ² , and the pressure oil at this pressure is used for the fishing devices 8, 10,. It is sent to 12. At this time, since the hydraulic pressure of the medium pressure value set by the third relief valve 102 acts on the pressure switching port of the main relief valve 108, the relief pressure is a pressure corresponding to the medium pressure value, that is, 145 kg / cm ^2. When the pressure of the oil supplied through the oil supply passage 14 exceeds 145 kg / cm ² , the main relief valve 108 is opened to prevent the pressure from rising abnormally, The returned oil is returned to the oil tank 6. As described above,
When the fishing devices 8, 10, and 12 are operated and the load is medium, the pressure of the oil supplied from the swash plate piston pump 4 becomes a medium pressure. , 12 can be operated efficiently as required.

The fishing devices 8, 10, 12 are in the operating state (the switching valves 8b, 10b, 12b of the fishing devices 8, 10, 12 are held in the first operating position or the second operating position). Thus, in a high load state where the load is large, the flow path switching valve 72 is positioned at the non-operation position. In this state, the communication by the flow path switching valve 72 is shut off, and the oil from the oil supply flow path 14 is supplied to the oil flow path 84 through the oil flow path 76. Therefore, when the pressure of the oil in the oil flow path 84 exceeds 205 kg / cm ² , the oil supplied from the oil supply flow path 14 to the oil flow path 84
Is returned to the oil tank 6 and thus the pressure of the oil fed from the swash plate piston pump 4 to the oil feed passage 14 is
The pressure is set to a pressure corresponding to the pressure set by the first relief valve 88. At this time, the pressure of the oil flowing through the oil supply passage 14 is set to the servo piston 49 in the same manner as described above.
Of the spool valve 70, the first pilot port of the spool valve 70, and the first port of the spool valve 70.
The pressure set by the relief valve 88 of
05 kg / cm ² acts. Therefore, when the supply amount of the oil flowing through the oil supply passage 14 increases and the pressure becomes larger than the combined pressure of the pressure acting on the second pilot port and the pressure of the pilot spring 91, the valve of the spool 70 valve The body moves rightward, the oil flow path 76 and the oil flow path 79 communicate with each other, and oil from the oil supply flow path 14 is supplied to the large pressure chamber 53 of the servo piston 49. At 1, the swash plate 40 (FIG. 2) moves to the left and the inclination angle of the swash plate 40 (FIG. 2) decreases, and the amount of oil supplied from the swash plate piston pump 4, thereby reducing the discharge pressure. On the other hand, when the supply amount of the oil flowing through the oil supply passage 14 decreases and the pressure becomes smaller than the combined pressure of the pressure acting on the second pilot port and the pressure of the pilot spring 91, the valve of the spool valve 70 The body moves to the left, the oil passage 79 and the oil passage 77 communicate with each other, the oil in the large pressure chamber 53 is returned to the oil tank 6, and the servo piston 49 moves to the right in FIG. Board 40
The inclination angle of (FIG. 2) increases, and the amount of oil supply from the swash plate piston pump 4 increases, thereby increasing the discharge pressure. Since the spool valve 70 operates as described above, the pressure of the oil supplied from the swash plate piston pump 4 becomes
For example, the pressure is set to a high pressure of 210 kg / cm ² , and pressurized oil of this pressure is sent to the fishing devices 8, 10 and 12. At this time, since the hydraulic pressure of the high pressure value set by the first relief valve 88 acts on the pressure switching port of the main relief valve 108, the relief pressure is a pressure corresponding to the high pressure value, that is, 215 kg / cm ^2. Is set to
The pressure of the oil supplied through the oil supply passage 14 is 215 k
When the pressure exceeds g / cm ² , the main relief valve 108 is opened to prevent an abnormal increase in pressure, and the blown oil is returned to the oil tank 6. As described above, when the fishing devices 8, 10, and 12 are operated and the load is large, the pressure of the oil supplied from the swash plate piston pump 4 becomes high, so that the high-load fishing device 8 is used. , 10 and 12 can be supplied with sufficient pressure oil.

Although the embodiment of the hydraulic drive device according to the present invention has been described above, the present invention is not limited to such an embodiment, and various changes and modifications can be made without departing from the scope of the present invention. It is.

For example, in the embodiment, as shown in FIG. 1, the flow path switching valve 72 is an electromagnetically operated valve, but is not limited to this, and a manually operated valve may be used.

Further, for example, in the embodiment, when the fishing devices 8, 10, and 12 are in the operating state, the discharge pressure of the pressure oil from the swash plate piston pump 4 is switched in three stages according to the load. However, the discharge pressure may be simply set to a low pressure and a high pressure in order to simplify the configuration. In such a case, for example, the flow path switching valve 72 is constituted by a valve selectively positioned between a first operating position and a non-operating position, and the oil flow paths 100, 10
The fourth and third relief valves 102 may be omitted.

[0028]

According to the hydraulic drive system of the first aspect of the present invention, since the swash plate piston pump is used as the hydraulic pump for supplying oil to the fishing device, the inclination angle of the swash plate is adjusted. In addition, the required amount of oil can be supplied to the fishing equipment. In addition, a constant discharge pressure type regulator is provided in association with the swash plate piston pump, and this regulator can set the pressure of the oil supplied from the swash plate piston pump to a low pressure and a high pressure. When the fishing device is inactive, the set pressure of the regulator is set to a low pressure value. At this time, the pressure of the oil supplied from the swash plate piston pump is set to a low pressure, and when the fishing device is not operated, the inclination angle of the swash plate is reduced, and the discharge amount from the swash plate piston pump is almost zero. (Zero), which reduces the swash plate piston pump's entrained torque,
With a simple configuration as a hydraulic drive system, it is possible to directly connect the swash plate piston pump and the prime mover without using a clutch means. When the fishing apparatus operates, the set pressure of the regulator is set to a high pressure value.
At this time, the pressure of the oil supplied from the swash plate piston pump is set to a high pressure, whereby sufficient pressure oil is supplied to the fishing apparatus.

According to the hydraulic drive system of the second aspect of the present invention, the main relief valve is disposed in the oil supply passage through which oil is supplied from the swash plate piston pump, and the pressure of the main relief valve is set. The pressure set by the first and second pressure setting means acts on the switching port. That is, when the high pressure value is set by the first pressure setting means, the high pressure value by the first pressure setting means acts on the pressure switching port of the main relief valve, so that the relief pressure of the main relief valve is reduced. A high pressure corresponding to the high pressure value is set. On the other hand, when the low pressure value is set by the second pressure setting means, the low pressure value by the second pressure setting means acts on the pressure switching port of the main relief valve. A low pressure corresponding to the low pressure value is set.

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit diagram schematically showing an embodiment of a hydraulic drive system for a fishing device according to the present invention.

FIG. 2 is a sectional view showing a swash plate piston pump of the hydraulic drive system of FIG. 1;

[Explanation of symbols]

 Reference Signs List 2 motor 4 swash plate piston pump 6 oil tank 8, 10, 12 fishing equipment 14 oil supply flow path 16 oil return flow path 20 constant discharge pressure type regulator 21 housing 32 cylinder block 34 cylinder 36 piston 40 swash plate 49 servo piston 51 , 53 Pressure chamber 64 Oil supply flow path 70 Spool valve 72 Flow path switching valve 88 First relief valve 98 Second relief valve 102 Third relief valve 108 Main relief valve

Claims (2)

[Claims] 1. A cylinder block in which a cylinder is defined, a piston slidably mounted on the cylinder block, a swash plate to which one end of the piston is connected, and a servo piston for controlling an inclination angle of the swash plate. A swash plate piston pump, a prime mover directly connected to the swash plate piston pump without a clutch means, and a constant discharge pressure regulator for controlling the operation of the servo piston;
An oil tank containing oil, and a fishing device for performing fishing work, wherein the oil tank and the swash plate piston pump are connected via an oil supply passage, and the swash plate piston pump and the fishing device Is connected via an oil supply flow path, the fishing device and the oil tank are connected via an oil return flow path, and the constant discharge pressure type regulator has a set pressure of a low pressure value, When the set pressure of the constant discharge pressure regulator is the low pressure value, the oil is supplied from the swash plate piston pump to the oil supply passage. The pressure of the oil is set low corresponding to the low pressure value, and when the set pressure of the constant discharge pressure type regulator is the high pressure value, the oil is sent from the swash plate piston pump to the oil supply passage. The pressure of the supplied oil is set high corresponding to the high pressure value. Hydraulic drive system for fishing equipment, characterized in that,. 2. The discharge pressure constant type regulator, comprising: first pressure setting means for setting a set pressure to a high pressure value;
A second pressure setting means for setting the set pressure to a low pressure value, and further comprising, in the oil supply flow path, a means for preventing an abnormal increase in the pressure of the oil flowing therethrough. A main relief valve is provided, and a set pressure of the first and second pressure setting means is applied to a pressure switching port of the main relief valve. When the high pressure value is set by the first pressure setting means, the high pressure value set by the first pressure setting means acts on the pressure switching port of the main relief valve, whereby the high pressure value is set. When the relief pressure of the main relief valve is set to a high pressure and the set pressure of the constant discharge pressure regulator is set to the low pressure value by the second pressure setting means, the second pressure setting means Set by the Claim pressure value acts on the pressure switching port of the main relief valve, thereby characterized in that the relief pressure of the main relief valve is set to a low pressure 1
The hydraulic drive system of the fishing equipment as described.