JP2007051622A - Liquid pressure feed pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid pressure feed pump capable of making delivery quantities of a plurality of pumps stable and uniform. <P>SOLUTION: This pump is provided with a relief valve 20 changing delivery quantity of an axial piston pump 10, a swash plate angle detector 17 detecting swash plate angle of a swash plate 13 of the axial piston pump 10, and a controller 18 adjusting delivery quantity of the axial piston pump 10 by controlling the relief valve 20 based on swash plate angle detected by the swash plate angle detector 17. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hydraulic pressure supply pump.

  2. Description of the Related Art In recent years, various types of internal combustion engines that drive a fuel injection pump and an exhaust valve drive device using hydraulic pressure that has been stored are provided. The hydraulic oil pressurized by the hydraulic pressure supply pump interlocked with the crankshaft of the engine is supplied to the accumulator, and the fuel injection pump and the exhaust valve drive device are controlled by controlling the supply of the accumulated hydraulic oil with an electromagnetic valve. The operation timing can be freely adjusted for each load.

  The hydraulic pressure supply pump is provided with a mechanism for keeping the discharge pressure of the hydraulic oil constant. This is because the pump discharge pressure is controlled to be constant by balancing the discharge pressure with the preset pilot fluid pressure, the spring force of the spring, and the like. The pressure and spring force are kept constant. Such a hydraulic pressure supply pump having a conventional pressure constant mechanism is disclosed in Patent Documents 1 and 2, for example.

JP-A-10-82353 JP 2000-18131 A

Here, as shown in FIG. 6, the discharge amount (capacity) of the hydraulic pressure supply pump having a constant pressure mechanism is variable between the maximum discharge amount (maximum capacity) and the minimum discharge amount (minimum capacity). When the discharge pressure is lower than the set pressure P (constant), the discharge amount is operated at the maximum. On the other hand, when the discharge pressure is higher than the set pressure P, the discharge amount is operated at the minimum. However, the pressure constant mechanism of the hydraulic pressure supply pump cannot completely keep the set pressure P constant, and actually has a slope θ ₀ as shown in FIG. Such a characteristic is called a drooping characteristic.

The set pressure P itself can be adjusted by changing the pilot fluid pressure and the spring set length, but the slope θ _{0 of the} drooping characteristic is determined by the mechanical characteristics such as the spring characteristics of the pump control unit and the valve clearance. For this reason, it is difficult to finely adjust to an arbitrary inclination (an arbitrary discharge amount is set for an arbitrary set pressure P). And, when the drooping characteristic becomes a Z-shaped pressure-discharge amount characteristic as much as possible due to mechanical characteristics, for example, a phenomenon that the discharge amount fluctuates unstable, a so-called hunting phenomenon may occur. . That is, in the conventional hydraulic pressure supply pump, as described above, it is difficult to correct the slope θ _{0 of the} drooping characteristic, so that the phenomenon that the discharge amount is not stable with respect to the set pressure (hunting phenomenon) is prevented. It was difficult.

The slope θ _{0 of the} drooping characteristic is derived from subtle individual differences in pump components, and varies even with the same type of pump. Therefore, when using multiple hydraulic pressure supply pumps in combination, the amount of discharge affects the life of the pumps. To make the life of each pump uniform, each pump is operated under substantially the same conditions. And it is best to make the discharge amount of each pump substantially the same. In addition, the slope θ ₀ of the drooping characteristic can be extremely increased, and the hunting phenomenon and variations in individual differences can be relatively reduced by mechanically devising the spring characteristics of the pump control unit, etc. It is possible. However, if the slope θ _{0 of the} drooping characteristic is too large, the change in the discharge pressure due to the change in the discharge amount becomes large, and the performance of the pressure constant mechanism that is the original purpose may be deteriorated. That is, also from these things, in order to stabilize and equalize the discharge amount of each pump with respect to an arbitrary set pressure, the drooping characteristic of the hydraulic pressure supply pump can be finely adjusted (pressure-discharge of each pump It is considered necessary to align the quantity characteristics).

  Accordingly, an object of the present invention is to solve the above-described problem, and an object of the present invention is to provide a hydraulic pressure supply pump that can make the discharge amounts of a plurality of pumps stable and uniform.

The hydraulic pressure supply pump according to the first invention for solving the above-described problems is as follows.
In the hydraulic pressure supply pump that controls the discharge pressure of the pump,
A discharge amount variable means for changing the discharge amount of the pump;
Detecting means for detecting the pump capacity or the discharge amount;
Control means for controlling the discharge amount variable means based on the pump capacity or discharge amount detected by the detection means to adjust the discharge pressure of the pump.

A hydraulic pressure supply pump according to a second invention that solves the above problem is the hydraulic pressure supply pump according to the first invention,
The control means presets a control amount of the discharge amount varying means according to the detected pump capacity or discharge amount, and controls the discharge pressure of the pump based on the control amount.

A hydraulic supply pump according to a third aspect of the present invention for solving the above problem is
In the hydraulic pressure supply pump according to the first invention,
The control means controls according to a deviation between the detected pump capacity or discharge amount and the target amount.

A hydraulic pressure supply pump according to a fourth invention for solving the above-described problem is
In the hydraulic pressure supply pump according to the first invention,
The control means presets the control amount of the discharge amount varying means according to the pump capacity or the discharge amount, while the deviation control amount according to the deviation between the detected pump capacity or the discharge amount and the target amount is set. It is characterized by being controlled.

A hydraulic supply pump according to a fifth aspect of the present invention for solving the above problem is
In the hydraulic pressure supply pump according to any one of the first to fourth inventions,
A connection passage connecting the suction passage and the discharge passage of the pump;
When the flow is allowed only in one direction in the connection passage, a valve for restricting the flow in the reverse direction is provided,
The valve is connected to the discharge amount varying means.

A hydraulic supply pump according to a sixth aspect of the present invention for solving the above-described problem is
In the hydraulic pressure supply pump according to any one of the first to fifth inventions,
The pump discharge pressure of the pump is adjusted by controlling a relief valve as the discharge amount varying means based on the detected pump displacement or deviation between the discharge amount and the target amount.

  According to the hydraulic pressure supply pump according to the first aspect of the invention, in the hydraulic pressure supply pump for controlling the discharge pressure of the pump, the discharge amount variable means for changing the discharge amount of the pump, and the detection for detecting the pump capacity or the discharge amount And a control means for adjusting the discharge pressure of the pump by controlling the discharge amount variable means based on the pump capacity or the discharge amount detected by the detection means to obtain a stable pump discharge amount. Can do.

  According to the hydraulic pressure supply pump according to the second invention, in the hydraulic pressure supply pump according to the first invention, the control means sets the control amount of the discharge amount varying means according to the detected pump capacity or the discharge amount. By adding the correction amount and controlling the discharge pressure of the pump based on the control amount, it is possible to intentionally give the pump a drooping characteristic and prevent a hunting phenomenon.

  According to a hydraulic pressure supply pump according to a third aspect of the invention, in the hydraulic pressure supply pump according to the first aspect of the invention, the control means detects the detected pump capacity or discharge amount and a target amount (for example, the discharge amount of a plurality of pumps). By controlling in accordance with the deviation from the average value), even when a plurality of the pumps are used at the same time, the respective discharge pressures can be made substantially constant.

  According to the hydraulic pressure supply pump according to the fourth aspect of the invention, in the hydraulic pressure supply pump according to the first aspect of the invention, the control means sets a correction amount to the control amount of the discharge amount varying means according to the pump capacity or the discharge amount. In addition, by controlling the discharge pressure of the pump based on the control amount, the pump is intentionally provided with a drooping characteristic, and the deviation between the detected pump capacity or the discharge amount and the target amount is controlled. By controlling by taking into account the corresponding deviation control amount, even when using multiple pumps with varying droop characteristics due to the mechanical characteristics of each individual at the same time, make each discharge pressure substantially constant It is easy to make the discharge amount substantially constant.

  According to a hydraulic pressure supply pump according to a fifth aspect of the present invention, in the hydraulic pressure supply pump according to any one of the first to fourth aspects of the present invention, the hydraulic pressure supply pump includes a connection passage that connects a suction passage and a discharge passage of the pump, When allowing flow in only one direction in the passage, a valve that restricts flow in the reverse direction is provided, and the valve can be connected to the discharge amount varying means to change the suction and discharge of the pump.

  According to the hydraulic pressure supply pump according to the sixth aspect of the present invention, in the hydraulic pressure supply pump according to any one of the first to fifth aspects, the pump is an axial piston pump, based on the swash plate angle of the axial piston pump. By controlling the relief valve as the discharge amount varying means to adjust the discharge pressure of the pump, the discharge amount can be accurately controlled with a simple configuration.

  Hereinafter, embodiments of a hydraulic pressure supply pump according to the present invention will be described in detail with reference to the drawings. 1 is a schematic configuration diagram of a hydraulic pressure supply pump according to an embodiment of the present invention, FIG. 2 is a block diagram of a control controller, FIG. 3 is a block diagram of another control controller, and FIG. 4 is a block diagram of still another control controller. 5 and 5 are schematic configuration diagrams of a hydraulic pressure supply pump according to another embodiment of the present invention.

  For example, three hydraulic pressure supply pumps 1 shown in FIG. 1 are provided in a marine internal combustion engine capable of forward and reverse rotation, and are driven in conjunction with a crankshaft of the engine. The hydraulic pressure supply pump 1 supplies hydraulic oil to a fuel injection pump that performs fuel injection provided in the internal combustion engine, a valve operating device that drives an exhaust valve, and the like according to the engine load.

  As shown in FIG. 1, the external shape of the hydraulic pressure supply pump 1 is formed by a casing 2. A switching valve 3 is provided in the upper part of the casing 2, and the switching valve 3 is composed of a spring 4 and a spool 5. The casing 2 outside the switching valve 3 supports a stopper 6 that restricts the movement of the spring 4 to the left in the figure by a predetermined amount or more. Further, a controller piston 7 is provided in the central portion of the casing 2, and the casings 2 on both sides thereof are provided with stoppers 8 for restricting movement of the controller piston 7 in the left direction in the drawing by a predetermined amount or more, Similarly, a stopper 9 that restricts movement of a predetermined amount or more in the right direction in the figure is supported.

  Further, a variable discharge amount type axial piston pump 10 is provided at the lower portion of the casing 2, and the axial piston pump 10 is composed of a cylinder 11, pistons 12 a and 12 b, and a swash plate 13. The cylinder 11 is rotatably supported by the casing 2 by being supported by the bearing 14 at one end and by the bearing 15 at the other end. One end thereof is connected to the crankshaft of the internal combustion engine. The swash plate 13 is connected to the controller piston 7 via the connecting member 16, and the swash plate angle is increased when the controller piston 7 moves in the left direction in the figure, and when the controller piston 7 moves in the right direction in the figure, the swash plate. Reduce the angle. The pistons 12a and 12b reciprocate in the axial direction of the cylinder 11 based on the rotational movement of the swash plate 13, and compression chambers 11a and 11b are formed by the reciprocating movement. That is, when the swash plate 13 tilts to the left in the figure, the discharge amount increases, and when it tilts to the right in the figure, the discharge amount decreases.

  A swash plate angle detector 17 for detecting a swash plate angle of the swash plate 13 is connected to the connecting member 16, and a controller 18 is connected to the swash plate angle detector 17. The controller 18 is connected to a crank angle sensor 19 that is provided on the crankshaft of the internal combustion engine and detects engine rotation, and is connected to a relief valve 20 that applies a set pressure to the switching valve 3.

  The hydraulic oil is supplied from the suction line 21 to the compression chamber 11b, pressurized, and supplied from the compression chamber 11a through the discharge line 22 to the fuel injection pump and the valve operating device. At this time, the hydraulic oil also flows into the branch line 23 branched from the discharge line 22, passes through the oil passage 24, and is also supplied to the A chamber formed on one end side of the controller piston 7. An oil passage 25 communicating with the switching valve 3 side is connected to the A chamber, and an oil passage 3a communicating with the B chamber formed at one end side of the switching valve 3 is formed. The oil passage 25 and the oil passage 3a are always in communication. On the other hand, when the switching valve 3 moves to the left in the drawing, the oil passage 25 is communicated with an oil passage 26 connected to the C chamber formed on the other end side of the controller piston 7. In addition, an orifice 28 for communicating with a drain line 27 is provided at an intermediate portion of the oil passage 26.

  An oil passage 29 communicating with the switching valve 3 side is connected to the relief valve 20, and this oil passage 29 is provided with an oil passage 29 a communicating with the D chamber formed on the switching valve 3 side and a spring 4. Branched to an oil passage 29b communicating with the E chamber. Further, an oil passage 30 communicating with the drain line 27 is connected to the opposite side of the relief valve 20 to which the oil passage 29 is connected.

  In other words, the combined force of the spring force of the spring 4 set in advance and the pressure supplied to the E chamber by the relief valve 20 is greater than the acting force in the left direction of the spool 5 due to the discharge pressure guided to the B chamber. When it becomes larger, the switching valve 3 is moved to the right in the figure, and the passage from the oil passage 25 to the oil passage 26 is closed, so that the hydraulic oil supply to the C chamber is cut off, while the controller piston 7 is pushed to the left in the figure by the pressure in the A chamber, and the hydraulic fluid in the C chamber is gradually discharged through the orifice 28 to the drain line 27. Further, a force obtained by combining the preset spring force of the spring 4 and the pressure supplied to the E chamber by the relief valve 20 is greater than the acting force in the left direction of the spool 5 due to the discharge pressure guided to the B chamber. When it becomes smaller, the switching valve 3 is moved to the left in the figure, and the passage from the oil passage 25 to the oil passage 26 is opened, so that hydraulic oil is supplied to the C chamber and the controller piston 7 is moved to the right. Move to.

  Accordingly, when the discharge pressure of the discharge line 22 rises, the acting force in the left direction in the figure due to the B chamber pressure of the spool 5 becomes larger than the combined force of the spring force of the spring 4 and the pressure of the relief valve 20. 3 is moved to the left side in the figure to supply the hydraulic oil guided to the A chamber to the C chamber. As a result, the controller piston 7 is moved rightward in the figure, the swash plate angle of the swash plate 13 is reduced, and the discharge amount is reduced. When the discharge pressure of the discharge line 22 decreases, the acting force in the left direction in the figure due to the B chamber pressure of the spool 5 becomes smaller than the combined force of the spring force of the spring 4 and the pressure of the relief valve 20. 3 is moved to the right side in the drawing, and the hydraulic oil guided to the C chamber is discharged from the drain line 27 through the orifice 28. Thereby, the controller piston 7 is moved in the left direction in the figure, the swash plate angle of the swash plate 13 is increased, and the discharge amount is increased.

  Here, in the hydraulic pressure supply pump 1 of the present invention, the set pressure of the relief valve 20 is changed as needed based on the discharge amount of the hydraulic oil, and the swash plate angle of the swash plate 13 is based on the swing position of the connecting member 16. The controller 18 calculates the current discharge amount from the swash plate angle, and controls the set pressure of the relief valve 20 in accordance with the discharge amount.

  Next, the configuration and processing method of the controller 18 will be described with reference to FIGS.

  First, as shown in FIG. 2, the controller 18 is connected to a reference discharge pressure calculation unit 31 connected to the crank angle sensor 19, and the reference discharge pressure calculation unit 31 and the swash plate angle detector 17. A drooping characteristic calculation unit 32 is provided.

  That is, the crank angle sensor 19 detects the engine speed N based on the crank angle detected every predetermined period, and outputs the engine speed N to the reference discharge pressure calculation unit 31. In the reference discharge pressure calculation unit 31, the relationship between the rotation speed and the discharge pressure is set in advance using a map, and the reference discharge pressure Po is calculated based on the rotation speed N from this map. In the drooping characteristic calculation unit 32, a map of the drooping characteristic correction amount (hereinafter referred to as drooping amount) with respect to the swash plate angle is set in advance (specifically, when the swash plate angle, that is, the discharge amount (pump capacity)) increases. The drooping amount is set according to the swash plate angle δ1 of the swash plate 13 detected by the swash plate angle detector 17 from this map, and the target discharge is calculated from the reference discharge pressure Po. The pressure Ps is determined. The target discharge pressure Ps is output as an electric signal and controls the relief valve 20. In the case where the hydraulic pressure is supplied by a plurality of pumps, such control is performed simultaneously in each of the hydraulic pressure supply pumps 1.

  Accordingly, the swash plate angle δ1 of the swash plate 13 is detected, that is, the discharge amount is detected, and the relief valve 20 is controlled with the target discharge pressure Ps corresponding thereto, so that the slope of the drooping characteristic as shown by the one-dot chain line in FIG. θ can be arbitrarily set. In other words, even if there is a variation in the drooping characteristics due to the mechanical characteristics of each solid, the drooping characteristics can be finely adjusted and arbitrarily set, so that a stable discharge amount with respect to the target discharge pressure Ps can be obtained ( Hunting prevention). Furthermore, when a plurality of units are operated, the discharge characteristics of each pump with respect to the target discharge pressure Ps can be made uniform by making the drooping characteristics set for each pump the same.

  Further, the controller 18 may be configured as shown in FIG. In addition, the same code | symbol is attached | subjected to the thing similar to what is shown in FIG. 2, and the description is abbreviate | omitted.

  As shown in FIG. 3, the control controller 18 includes a reference discharge pressure calculation unit 31 connected to the crank angle sensor 19 and an average connected to the swash plate angle detector 17 installed in each hydraulic pressure supply pump 1. A value calculation unit 33, a PID calculation unit 35 connected to the average value calculation unit 33 via a subtractor 34, and an adder 36 connected to the reference discharge pressure calculation unit 31 and the PID calculation unit 35 are provided. ing.

  The average value calculation unit 33 calculates an average value δm of the swash plate angles δ1, δ2, and δ3 detected by the swash plate angle detector 17 provided in each hydraulic pressure supply pump 1. The PID calculation unit 35 includes a proportional calculation unit 37, an integral calculation unit 38, a differential calculation unit 39, and an adder 40. Based on the difference Δδ between the average value δm obtained by the subtractor 34 and the swash plate angle δ1. Proportional control, integral control, and differential control are performed, and the sum of each control is calculated as a correction value.

  That is, the crank angle sensor 19 detects the engine speed N based on the crank angle detected every predetermined period, and outputs the engine speed N to the reference discharge pressure calculation unit 31. On the other hand, the swash plate angles δ 1, δ 2 and δ 3 detected by each swash plate angle detector 17 are output to the average value calculation unit 33. After the average value δm of the swash plate angle is calculated by the average value calculation unit 33, the difference Δδ 1 between the average value δm and the swash plate angle δ 1 is calculated by the subtractor 34 and output to the PID calculation unit 35.

  The PID calculation unit 35 performs PID control based on the difference Δδ1, for example, the proportional calculation unit 37 calculates a proportional term αp that is controlled in proportion to the difference Δδ1, and the integral calculation unit 38 calculates a slight difference Δδ1 over time. The integral term αi to be controlled is calculated when the difference reaches a predetermined amount, and the derivative calculation unit 39 calculates the differential term αd to be controlled by looking at the change difference from the previously calculated difference Δδ1. Then, the adder 40 outputs the sum of the proportional term αp, the integral term αi, and the derivative term αd to the adder 36.

  In the adder 36, the relief valve set pressure Pf is calculated by adding the proportional term αp, the integral term αi, and the derivative term αd to the reference discharge pressure Po calculated by the reference discharge pressure calculation unit 31. And the relief valve 20 is controlled so that it may become the relief valve setting pressure Pf.

  The same control is performed in the other two hydraulic pressure supply pumps 1, and the second hydraulic pressure supply pump 1 takes into account the PID control amount corresponding to the difference Δδ2 to the reference discharge pressure Po. In the second hydraulic pressure supply pump 1, a PID control amount corresponding to the difference Δδ3 is added to the reference discharge pressure Po. In this embodiment, three hydraulic pressure supply pumps 1 are provided. However, the number is not limited to this, and control is possible if two or more hydraulic supply pumps 1 are provided.

  Accordingly, when a plurality of hydraulic pressure supply pumps 1 are used simultaneously, the swash plate angles δ1, δ2, and δ3 of the swash plate 13 are detected, that is, the discharge amounts are detected, and the respective discharge amounts are compared. Since substantially the same discharge amount can be stably obtained, it is possible to prevent a problem that only the life of one of the hydraulic pressure supply pumps 1 is shortened.

  Further, the controller 18 may be configured as shown in FIG. In addition, the same code | symbol is attached | subjected to the thing similar to what is shown in FIG.2, 3, The description is abbreviate | omitted.

  As shown in FIG. 4, the controller 18 includes a reference discharge pressure calculation unit 31 connected to the crank angle sensor 19 and a drooping characteristic connected to the reference discharge pressure calculation unit 31 and the swash plate angle detector 17. A calculation unit 32, an average value calculation unit 33 connected to the swash plate angle detector 17 installed in each hydraulic pressure supply pump 1, and a PID calculation unit connected to the average value calculation unit 33 via a subtractor 34 35 and an adder 36 connected to the reference discharge pressure calculation unit 31 and the PID calculation unit 35 are provided.

  That is, the crank angle sensor 19 detects the engine speed N based on the crank angle detected every predetermined period, and outputs the engine speed N to the reference discharge pressure calculation unit 31. In the reference discharge pressure calculation unit 31, the relationship between the rotation speed and the discharge pressure is set in advance by a map, and the reference discharge pressure Po is calculated from the map based on the rotation speed N and output to the drooping characteristic calculation unit 32. . In the drooping characteristic calculation unit 32, the drooping amount with respect to the swash plate angle is set in advance, and the drooping amount is calculated according to the swash plate angle δ1 of the swash plate 13 detected by the swash plate angle detector 17 from this map, The target discharge pressure Ps is determined from the reference discharge pressure Po. The calculated target discharge pressure Ps is output to the adder 36.

  On the other hand, the swash plate angles δ 1, δ 2 and δ 3 detected by each swash plate angle detector 17 are output to the average value calculation unit 33. After the average value δm of the swash plate angle is calculated by the average value calculation unit 33, the difference Δδ 1 between the average value δm and the swash plate angle δ 1 is calculated by the subtractor 34 and output to the PID calculation unit 35. In the PID calculation unit 35, PID calculation is performed based on the difference Δδ1, and the proportional term αp, the integral term αi, and the differential term αd are calculated by the proportional calculation unit 37, the integral calculation unit 38, and the differential calculation unit 39, respectively. 40 is output.

  The adder 36 calculates the relief valve set pressure Pf by adding the proportional term αp, the integral term αi, and the differential term αd to the target discharge pressure Ps calculated by the drooping characteristic calculation calculation unit 32. And the relief valve 20 is controlled so that it may become the relief valve setting pressure Pf.

  The other two hydraulic pressure supply pumps 1 perform the same control, and the second hydraulic pressure supply pump 1 adds a PID control amount corresponding to the difference Δδ2 to the target discharge pressure Ps. In the second hydraulic pressure supply pump 1, a PID control amount corresponding to the difference Δδ3 is added to the target discharge pressure Ps. In this embodiment, three hydraulic pressure supply pumps 1 are provided. However, the number is not limited to this, and control is possible if two or more hydraulic supply pumps 1 are provided. Further, when there is one hydraulic pressure supply pump 1, a reference value (target value) corresponding to the average value δm is set, and the difference between the detected swash plate angle δ1 and the reference value is calculated by PID. You may make it make the part 35 output.

  Accordingly, the swash plate angle δ1 of the swash plate 13 is detected, that is, the discharge amount is detected, the target discharge pressure Ps is calculated accordingly, and the PID control amount for the average value δm is added to the target discharge pressure Ps. Thus, the discharge pressure of each pump can be made more accurate and, as a result, the discharge amount of each pump can be controlled stably and substantially the same. Therefore, it is possible to prevent the problem that only the life of one of the hydraulic pressure supply pumps 1 is shortened.

  Further, when the hydraulic pressure supply pump 1 is provided in a marine internal combustion engine capable of forward and reverse rotation, a configuration as shown in FIG. 5 may be used.

  In this configuration, a connection line 41 that connects the suction line 21 and the supply line 22 is connected, and the branch line 23 is connected to a shuttle valve 42 provided on the connection line 41. The shuttle valve 42 restricts the flow in the reverse direction when allowing the flow of hydraulic oil in only one direction.

  For example, when the engine rotates in the forward direction, the hydraulic oil is supplied from the suction line 21 to the compression chamber 11b, pressurized and supplied from the compression chamber 11a through the discharge line 22 to the fuel injection pump, the valve operating device, and the like. And flows to the branch line 23 through the shuttle valve 42. When the engine rotates in reverse, the hydraulic oil is supplied from the discharge line 22 to the compression chamber 11a, pressurized and supplied from the compression chamber 11b through the suction line 21 to the fuel injection pump, the valve gear, and the like. And flows to the branch line 23 through the shuttle valve 42. Note that the flow of hydraulic oil at the time of forward rotation and reverse rotation of the engine may be reversed. Therefore, even with such a configuration in which the shuttle valve 42 is provided, the above-described effects can be obtained.

  Therefore, according to the hydraulic pressure supply pump of the present invention, the relief valve 20 that changes the discharge amount of the axial piston pump 10, and the swash plate angle detector 17 that detects the swash plate angle of the swash plate 13 of the axial piston pump 10, And a controller 18 that controls the relief valve 20 based on the swash plate angle detected by the swash plate angle detector 17 to adjust the discharge amount of the axial piston pump 10, thereby providing a spring having mechanical characteristics. 4 can be used to easily control the set pressure of the relief valve 20, so that a stable pump discharge amount can be obtained.

  Further, since the set pressure of the relief valve 20 is set in advance according to the swash plate angle, and the discharge amount of the axial piston pump 10 is controlled based on the set pressure, the slope of the drooping characteristic can be arbitrarily set. Even if the drooping characteristic varies depending on the mechanical characteristics of each individual, the hunting phenomenon can be prevented.

  Even when a plurality of pumps are used at the same time, by controlling according to the deviation between one swash plate angle and the average swash plate angle, it is possible to make each discharge amount substantially constant.

  In addition, while setting the preset pressure of the relief valve 20 according to the swash plate angle, the slope of the drooping characteristic can be reduced by adding the PID control amount according to the deviation between the swash plate angle and the average value to the set pressure. Since it can be set arbitrarily, the hunting phenomenon can be prevented even if the drooping characteristic varies depending on the mechanical characteristics of each individual. In addition, since each discharge amount can be made substantially constant, it is possible to prevent the problem that only the life of one of the hydraulic pressure supply pumps 1 is shortened.

  In addition, a connection line 41 that connects the suction line 21 and the discharge line 22 is provided, and when the flow is allowed only in one direction in the connection line 41, a shuttle valve 42 that restricts the flow in the reverse direction is provided. By connecting the branch line 23 communicating with the valve 20 side, the suction and discharge of the axial piston pump 10 can be changed, so that it can be easily provided in a marine internal combustion engine capable of forward and reverse rotation.

  Furthermore, since the discharge amount is adjusted by controlling the relief valve 20 based on the swash plate angle of the axial piston pump 10, the discharge amount can be accurately controlled with a simple configuration.

  The present invention can be applied to a hydraulic pressure supply pump having a mechanism for keeping the pressure constant.

It is a schematic block diagram of the hydraulic pressure supply pump which concerns on one Example of this invention. It is a block diagram of a control controller. It is a block diagram of another control controller. It is a block diagram of still another control controller. It is a schematic block diagram of the hydraulic pressure supply pump which concerns on the other Example of this invention. It is a figure which shows the relationship between the discharge pressure at the time of a fixed pressure, and discharge amount. It is the figure which showed the drooping characteristic.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydraulic pressure pump 2 Casing 3 Switching valve 3a Oil path 4 Spring 5 Spool 6, 8, 9 Stopper 7 Controller piston 10 Axial piston pump 11 Cylinder 11a, 11b Compression chamber 12a, 12b Piston 13 Swash plate 14, 15 Bearing 16 Connecting member 17 Swash plate angle detector 18 Controller 19 Crank angle sensor 20 Relief valve 21 Suction line 22 Discharge line 23 Branch lines 24, 25, 26, 29, 30 Oil passage 27 Drain line 28 Orifice 31 Reference discharge pressure calculation unit 32 Droop characteristic calculator 33 Average value calculator 34 Subtractor 35 PID calculators 36 and 40 Adder 37 Proportional calculator 38 Integral calculator 39 Differential calculator 41 Connection line 42 Shuttle valve

Claims (6)

In the hydraulic pressure supply pump that controls the discharge pressure of the pump,
A discharge amount variable means for changing the discharge amount of the pump;
Detecting means for detecting the pump capacity or the discharge amount;
A hydraulic pressure supply pump comprising: control means for controlling the discharge amount variable means based on the pump capacity or discharge amount detected by the detection means to adjust the discharge pressure of the pump. The hydraulic supply pump according to claim 1,
The control means presets a control amount of the discharge amount varying means in accordance with the detected pump capacity or discharge amount, and controls the discharge pressure of the pump based on the control amount. . The hydraulic supply pump according to claim 1,
The said control means controls according to the deviation of the detected pump capacity | capacitance or discharge amount, and target amount. The hydraulic pressure supply pump characterized by the above-mentioned. The hydraulic supply pump according to claim 1,
The control means presets the control amount of the discharge amount varying means according to the pump capacity or the discharge amount, while the deviation control amount according to the deviation between the detected pump capacity or the discharge amount and the target amount is set. A hydraulic pressure supply pump characterized by being controlled. The hydraulic supply pump according to any one of claims 1 to 4,
A connection passage connecting the suction passage and the discharge passage of the pump;
When the flow is allowed only in one direction in the connection passage, a valve for restricting the flow in the reverse direction is provided,
A hydraulic pressure supply pump characterized in that the valve is connected to the discharge amount varying means. The hydraulic supply pump according to any one of claims 1 to 5,
The pump is an axial piston pump, and the discharge pressure of the pump is adjusted by controlling a relief valve as the discharge amount varying means based on the swash plate angle of the axial piston pump. Supply pump.

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