JP2018150871A - Servo regulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the control characteristics of a servo regulator.SOLUTION: A servo regulator 100 includes a servo piston 20, a first pressure chamber 54a and a second pressure chamber 54b, a first spool 30a and a second spool 30b, a first spool spring 37a and a second spool spring 37b, a feedback link 80 to be turned in response to the movement of the servo piston 20 for changing the energizing force of each of the first spool spring 37a and the second spool spring 37b, and a restriction member 90 supported on a first case member 51 movably in the turn center axis direction of the feedback link 80 for restricting the tilt of the feedback link 80 while holding the feedback link 80 between the first case member 51 and itself.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a servo regulator.

  In a variable displacement piston pump (hereinafter simply referred to as “piston pump”) mounted on a vehicle such as a construction machine, the displacement of the servo piston of the servo regulator is transmitted to the swash plate of the piston pump to tilt the swash plate. Thus, the discharge flow rate of the piston pump is adjusted.

  In the servo regulator disclosed in Patent Document 1, the servo piston is displaced by the hydraulic oil supplied to the pressure chamber. The pressure chamber is connected to the pump through a port that is opened and closed by a spool. When the spool moves due to the thrust of the solenoid, the pressure chamber is connected to the pump through the port, and hydraulic oil is supplied to the pressure chamber.

  Further, in the servo regulator disclosed in Patent Document 1, the movement of the servo piston is transmitted to the feedback spring through a feedback link that is rotatably supported by the support shaft. When the urging force of the feedback spring changes, the spool moves so that the urging force of the feedback spring and the thrust of the solenoid are balanced. Thereby, the pressure in the pressure chamber is automatically adjusted so as to keep the servo piston at a desired position. As a result, the tilt angle of the swash plate of the variable displacement piston pump is maintained at a desired angle.

JP 2009-243435 A

  In the servo regulator disclosed in Patent Literature 1, the feedback link is inclined with respect to the support shaft, and the rotation center axis of the feedback link may be displaced. In this case, the ratio between the distance between the rotation center axis and the servo piston and the distance between the rotation center axis and the feedback spring varies, and the expansion / contraction amount of the feedback spring varies with respect to the movement amount of the servo piston. As a result, the feedback spring cannot exert an urging force corresponding to the amount of movement of the servo piston, and there is a possibility that desired control characteristics cannot be obtained. For this reason, it is required to improve the control characteristics of the servo regulator by regulating the inclination of the feedback link.

  In Patent Document 1, the inclination of the feedback link is regulated by a snap ring fixed to the tip of the support shaft and a step formed on the outer periphery of the support shaft. If the distance between the stepped portion and the snap ring is too large with respect to the thickness of the feedback link, the inclination of the feedback link is not sufficiently restricted, and desired control characteristics cannot be obtained. Further, if the distance between the stepped portion and the snap ring is small with respect to the thickness of the feedback link, the feedback ring is sandwiched between the stepped portion and the snap ring, and friction occurs in the feedback link. Therefore, the operation of the feedback link is hindered and desired control characteristics cannot be obtained.

  Thus, in the servo regulator disclosed in Patent Document 1, it is necessary to strictly manage tolerances such as the thickness of the feedback link and the gap between the stepped portion and the snap ring, and it is difficult to improve the control characteristics of the servo regulator. is there.

  An object of the present invention is to improve the control characteristics of a servo regulator.

  According to a first aspect of the present invention, there is provided a servo piston, a pressure chamber, a spool, an urging member, a feedback unit that rotates according to the movement of the servo piston and changes the urging force of the urging member, and a rotation of the feedback unit. And a regulating member that is supported by the case so as to be movable in the direction of the movement center axis, and that regulates the inclination of the feedback unit with the feedback unit sandwiched between the case and the case.

  In the first invention, the restricting member is supported by the case so as to be movable in the direction of the rotation center axis of the feedback portion. Therefore, the distance between the regulating member and the case can be changed by moving the regulating member with respect to the case. Therefore, regardless of the forming accuracy of the feedback part and the regulating member, it is possible to reduce the friction of the feedback part while regulating the inclination of the feedback part.

  The second invention is characterized in that the regulating member is screwed into the case and moves in the direction of the rotation center axis in accordance with the amount of rotation with respect to the case.

  In the second aspect of the invention, since the regulating member is screwed and moves according to the rotation amount, the movement amount of the regulating member can be easily managed. Therefore, the distance between the regulating member and the case can be easily managed, and the control characteristics of the servo regulator can be improved.

  According to a third aspect of the present invention, the feedback portion has a center hole that passes through the rotation center, the restriction member has a support portion that is inserted into the center hole and rotatably supports the feedback portion, and the support portion is It is characterized by being eccentric with respect to the rotation center axis of the restricting member.

  In the third invention, since the support portion is eccentric with respect to the rotation center axis of the restriction member, the rotation center axis of the feedback portion is displaced according to the rotation of the restriction member. Since the feedback unit changes the urging force of the urging member, the neutral position of the spool can be adjusted by the displacement of the rotation center axis. Further, since the neutral position adjustment is completed when the regulating member is rotated half a turn at the maximum, the distance between the case and the regulating member can be set within a range from a desired value within a half pitch of the screw.

  According to a fourth aspect of the present invention, the feedback portion has a center hole that passes through the rotation center, and the case has a support portion that is inserted into the center hole and rotatably supports the feedback portion.

  In the fourth invention, since the case has the support portion, the rotation center axis of the feedback portion is determined by the case. Therefore, it is possible to change the interval between the case and the regulating member by rotating the regulating member without displacing the rotation center axis of the feedback unit, and it is possible to easily improve the control characteristics of the servo regulator.

  According to a fifth aspect of the present invention, the regulating member extends from the support portion along the rotation center axis of the feedback portion and is supported by the case, and extends from the support portion to the opposite side of the first shaft portion. And a second shaft portion supported by the existing case.

  In the fifth invention, both the first shaft portion and the second shaft portion are supported by the case, and the restricting member is supported at both ends by the case. Therefore, deformation of the restricting member can be reduced. Therefore, it is possible to reduce the inclination of the feedback unit and reduce friction caused by the inclination. As a result, the control characteristics of the servo regulator are improved.

  The sixth invention is characterized in that the outer diameter of the second shaft portion is smaller than the outer diameter of the first shaft portion, and the second shaft portion is screwed into the case.

  In the sixth invention, the second shaft portion having an outer diameter smaller than the outer diameter of the first shaft portion is screwed into the case. Therefore, the pitch of the male screw can be reduced, and the amount of movement of the regulating member per rotation can be reduced. Therefore, even when the neutral position of the spool is adjusted by rotating the regulating member, the interval between the case and the regulating member can be set within a narrower range.

  The seventh invention is characterized in that the restricting member is screwed with an inner peripheral surface of a hole opened in the outer side surface of the case.

  In the seventh invention, the restricting member is screwed with the inner peripheral surface of the hole opened in the outer surface of the case. Therefore, when forming the female screw on the inner peripheral surface of the hole, it is easy to put the jig into the hole, and the coaxiality of the female screw can be easily ensured. Therefore, the inclination of the regulating member due to the inclination of the female screw can be prevented, and the inclination of the feedback portion can be prevented. As a result, the control characteristics of the servo regulator can be improved.

  In the eighth aspect of the invention, the regulating member has a male screw that is screwed with the inner peripheral surface of the hole and screwed with the fixing member.

  In the eighth invention, the male screw of the restricting member is screwed with the inner peripheral surface of the hole and screwed with the fixing member. Therefore, it is only necessary to form one type of male screw on the regulating member, and the regulating member can be easily manufactured. Therefore, the servo regulator can be easily manufactured.

  According to the present invention, the control characteristics of the servo regulator can be improved.

It is sectional drawing of the servo regulator which concerns on embodiment of this invention, and shows the state attached to the variable displacement type piston pump. It is a partial cross section figure of the servo regulator which follows the II-II line of FIG. It is a partially expanded sectional view which shows the periphery of a 1st spool and a 2nd spool, and shows the state which the solenoid is not operate | moving. It is sectional drawing of a servo regulator, and shows the connection of a servo piston and a feedback link corresponding to FIG. It is a partially expanded sectional view which shows the periphery of a control member. It is an enlarged view of a regulating member. It is a partially expanded sectional view which shows the periphery of a 1st spool and a 2nd spool, and shows the state which the solenoid is operate | moving. It is a figure for demonstrating the assembly method of a servo regulator, and shows the state which connected the feedback link to the servo piston. It is a figure for demonstrating the assembly method of a servo regulator, and shows the state which inserted the control member in the hole of the 1st case member. It is sectional drawing of the servo regulator which concerns on 2nd Embodiment of this invention, and shows corresponding to FIG. It is sectional drawing of the servo regulator which concerns on 3rd Embodiment of this invention, and shows corresponding to FIG.

  Hereinafter, servo regulators 100, 200, and 300 according to embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
First, a servo regulator 100 according to a first embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the pump apparatus 1000 includes a variable displacement piston pump 1 and a servo regulator 100 assembled to the piston pump 1. The piston pump 1 is used in a hydrostatic continuously variable transmission (HST) that supplies hydraulic oil to a traveling hydraulic motor of a vehicle such as a construction machine.

  The piston pump 1 includes a swash plate 3 rotatably provided in a housing 2 via a pair of trunnion shafts 3a, and a cylinder block 4 that is rotated by the power of a vehicle engine. The rotation center axis 4C of the cylinder block 4 intersects the rotation center axis 3C of the swash plate 3.

  A plurality of cylinders (not shown) are formed in the cylinder block 4. The plurality of cylinders extend along the rotation center axis 4C of the cylinder block 4 and are arranged around the rotation center axis 4C.

  A piston (not shown) is slidably accommodated in the cylinder, and a volume chamber is defined in the cylinder by the piston. The volume chamber communicates alternately with the suction port and the discharge port as the cylinder block 4 rotates.

  One end of the piston contacts the swash plate 3 via a piston shoe (not shown). In a state where the swash plate 3 is inclined with respect to the rotation center axis 4C of the cylinder block 4, the piston moves relative to the cylinder block 4 as the cylinder block 4 rotates, and the volume of the volume chamber changes.

  In the suction stroke in which the piston moves in the cylinder so that the volume chamber expands, the hydraulic oil is sucked into the volume chamber through the suction port. In the discharge stroke in which the piston moves in the cylinder so that the volume chamber shrinks, the hydraulic oil is discharged from the volume chamber to the discharge port.

  In the piston pump 1, the stroke amount of the piston can be changed by changing the angle (tilt angle) of the swash plate 3 with respect to the rotation center axis 4 </ b> C of the cylinder block 4. Thereby, the flow rate of the hydraulic oil discharged from the piston pump 1 can be changed.

  When the tilt angle of the swash plate 3 is 0 ° (zero degree), that is, when the swash plate 3 is in the neutral position, the piston does not move relative to the cylinder block 4 despite the rotation of the cylinder block 4. Therefore, the volume of the volume chamber does not change, and the discharge flow rate of the piston pump 1 is 0 (zero). The hydraulic oil is not supplied to the traveling hydraulic motor, and the traveling hydraulic motor stops rotating.

  The piston pump 1 is a two-way discharge type pump, and the port through which hydraulic oil is sucked or discharged is switched by switching the tilt direction of the swash plate 3 with a tilt angle of 0 ° as a boundary. By switching the discharge direction of the hydraulic oil from the piston pump 1, the rotational direction of the traveling hydraulic motor is changed, and the vehicle is switched between forward and reverse.

  As shown in FIGS. 1 and 2, the servo regulator 100 includes a servo piston 20, a first spool (spool) 30 a and a second spool (spool) 30 b that control the pressure of hydraulic oil acting on the servo piston 20, Is provided. The servo piston 20 is connected to the swash plate 3 of the piston pump 1 via the arm 10. The first spool 30a and the second spool 30b are moved by a first solenoid (solenoid) 40a and a second solenoid (solenoid) 40b, respectively.

  The servo piston 20, the first spool 30a and the second spool 30b are accommodated in the case 50. The case 50 has a first case member 51 attached to the housing 2 of the piston pump 1 and a second case member 52 attached to the first case member 51.

  A first accommodation hole 51 a is formed in the first case member 51, and a second accommodation hole 52 a is formed in the second case member 52. In a state where the second case member 52 is attached to the first case member 51, the first accommodation hole 51a and the second accommodation hole 52a are substantially parallel. The servo piston 20 is slidably accommodated in the first accommodation hole 51a, and the first spool 30a and the second spool 30b are accommodated in the second accommodation hole 52a.

  Both open ends of the first accommodation hole 51a are closed by the first cover 53a and the second cover 53b, respectively. The interior of the first accommodation hole 51a is partitioned by the servo piston 20 into a first pressure chamber (pressure chamber) 54a and a second pressure chamber (pressure chamber) 54b. Specifically, the first pressure chamber 54a is defined by the inner peripheral surface of the first accommodation hole 51a, one end surface of the servo piston 20, and the first cover 53a, and is provided to face one end surface of the servo piston 20. It is done. Similarly, the second pressure chamber 54b is defined by the inner peripheral surface of the first accommodation hole 51a, the other end surface of the servo piston 20 and the second cover 53b, and is provided to face the other end surface of the servo piston 20.

  The servo piston 20 moves in the first accommodation hole 51a by the pressure of the hydraulic oil in the first pressure chamber 54a and the second pressure chamber 54b. When the pressure in the first pressure chamber 54a is larger than the pressure in the second pressure chamber 54b, the servo piston 20 expands the first pressure chamber 54a and contracts the second pressure chamber 54b (right side in FIG. 2). Direction). When the pressure in the second pressure chamber 54b is larger than the pressure in the first pressure chamber 54a, the servo piston 20 expands the second pressure chamber 54b and reduces the first pressure chamber 54a (the left side in FIG. 2). Direction).

  The servo piston 20 is guided by a guide rod 56 that is fixed to the first cover 53a. An accommodation recess 21 capable of accommodating a first retainer 57 and a second retainer 58 attached to the outer periphery of the guide rod 56 is formed at the rod side end of the servo piston 20. Further, the servo piston 20 is formed with a guide hole 22 extending in the axial direction from the bottom surface 21 a of the housing recess 21.

  The guide rod 56 and the servo piston 20 are arranged coaxially. The distal end portion 56 a of the guide rod 56 has a diameter larger than that of the shaft portion 56 b and is slidably inserted into the guide hole 22 of the servo piston 20.

  A first retainer 57 and a second retainer 58 are slidably provided on the shaft portion 56 b of the guide rod 56. Between the first retainer 57 and the second retainer 58, a first piston spring 59a and a second piston spring 59b are provided in a compressed state. The first piston spring 59a and the second piston spring 59b urge the servo piston 20 to the neutral position.

  As shown in FIG. 2, when the servo piston 20 is in the neutral position, the first retainer 57 contacts the stopper ring 23 fixed to the opening end of the housing recess 21 and is screwed to the shaft portion 56b. It is in contact with the nut 56d. The second retainer 58 abuts on the bottom surface 21 a of the housing recess 21 of the servo piston 20 and abuts on a step portion 56 c formed between the distal end portion 56 a of the guide rod 56 and the shaft portion 56 b.

  When the servo piston 20 moves in the P1 direction from the neutral position, the first retainer 57 is pushed by the stopper ring 23 fixed to the servo piston 20. As a result, the first retainer 57 moves along the shaft portion 56b of the guide rod 56 so as to be separated from the nut 56d that is screwed into the shaft portion 56b of the guide rod 56.

  At this time, the second retainer 58 contacts the stepped portion 56 c of the guide rod 56 and does not move relative to the guide rod 56. Therefore, the first piston spring 59a and the second piston spring 59b between the first retainer 57 and the second retainer 58 are compressed, and the spring reaction force for returning the servo piston 20 to the neutral position is increased.

  On the other hand, when the servo piston 20 moves in the P2 direction from the neutral position, the second retainer 58 is pushed by the bottom surface 21a of the servo piston 20. As a result, the second retainer 58 moves along the shaft portion 56 b of the guide rod 56 so as to be separated from the step portion 56 c of the guide rod 56.

  At this time, the first retainer 57 contacts the nut 56 d and does not move relative to the guide rod 56. Therefore, the first piston spring 59a and the second piston spring 59b between the first retainer 57 and the second retainer 58 are compressed, and the spring reaction force for returning the servo piston 20 to the neutral position is increased.

  The neutral position of the servo piston 20 can be adjusted by adjusting the fastening position of the guide rod 56 with respect to the first cover 53a and fixing the guide rod 56 to the first cover 53a via the nut 56e.

  As shown in FIGS. 1 and 2, an annular groove 24 is formed on the outer periphery of the center of the servo piston 20 in the axial direction. The arm 10 is connected to the annular groove 24.

  Specifically, a pin 12 is provided at the tip of the arm 10, and a slide metal 13 is rotatably supported on the pin 12. The slide metal 13 is inserted into the annular groove 24 of the servo piston 20.

  Thus, the arm 10 is connected to the annular groove 24 via the pin 12 and the slide metal 13. 2, illustration of the arm 10, the pin 12, and the slide metal 13 is omitted.

  When the servo piston 20 moves, the slide metal 13 moves together with the servo piston 20. As a result, the arm 10 rotates about the rotation center shaft 3C, and the swash plate 3 tilts. Thus, the displacement of the servo piston 20 is transmitted to the swash plate 3 via the arm 10. As the swash plate 3 tilts, the discharge flow rate of the piston pump 1 changes.

  As shown in FIGS. 2 and 3, the first spool 30 a and the second spool 30 b are arranged coaxially in the second accommodation hole 52 a of the second case member 52. The first spool 30a controls the pressure in the first pressure chamber 54a, and the second spool 30b controls the pressure in the second pressure chamber 54b.

  Cylindrical first sleeve 60a and second sleeve 60b are provided at both end positions of second housing hole 52a. The base end portion 31a of the first spool 30a is slidably inserted into the first sleeve 60a, and the base end portion 31b of the second spool 30b is slidably inserted into the second sleeve 60b.

  The first sleeve 60a includes a supply port 61a connected to the hydraulic pump (fluid pressure source) 5 via the supply passage 5a, and a main port 62a connected to the first pressure chamber 54a via the main passage 6a. Prepare. The second sleeve 60b includes a supply port 61b connected to the hydraulic pump 5 via the supply passage 5b, and a main port 62b connected to the second pressure chamber 54b via the main passage 6b.

  Drain passages 7a and 7b connected to the tank 7 open on the inner peripheral surface of the second accommodation hole 52a. The openings of the drain passages 7a and 7b are located between the first sleeve 60a and the second sleeve 60b.

  An annular groove 33a, an annular groove 34a, and a protrusion 35a are formed on the outer periphery of the base end portion 31a of the first spool 30a. The annular groove 33a connects the supply port 61a and the main port 62a according to the position of the first spool 30a. The annular groove 34a connects the main port 62a and the drain passage 7a according to the position of the first spool 30a.

  The outer shape of the protrusion 35a is formed in a substantially triangular shape so as not to close the opening of the first sleeve 60a. Therefore, even when the protrusion 35a is in contact with the first sleeve 60a, the annular groove 34a always communicates with the drain passage 7a through the space between the protrusion 35a and the first sleeve 60a. 2 and 3 show a state in which the first spool 30a is arranged so that one of the substantially triangular apexes is located above the drawing and the opposite side of the apex is located below the drawing.

  An annular groove 33b, an annular groove 34b, and a protrusion 35b are formed on the outer periphery of the base end portion 31b of the second spool 30b. The annular groove 33b connects the supply port 61b and the main port 62b according to the position of the second spool 30b. The annular groove 34b connects the main port 62b and the drain passage 7b according to the position of the second spool 30b.

  The outer shape of the protrusion 35b is formed in a substantially triangular shape so as not to close the opening of the second sleeve 60b. Therefore, even when the protrusion 35b is in contact with the second sleeve 60b, the annular groove 34b always communicates with the drain passage 7b through the space between the protrusion 35b and the second sleeve 60b. 2 and 3 show a state in which the second spool 30b is arranged so that one of the substantially triangular apexes is located above the drawing and the opposite side of the apex is located below the drawing.

  A substantially cylindrical spring holder 70 is provided at a substantially central position of the second accommodation hole 52a. The leading end 32 a of the first spool 30 a and the leading end 32 b of the second spool 30 b are inserted into the spring holder 70.

  A first retainer 36a is fixed to the outer periphery at the center in the axial direction of the first spool 30a so as to abut against the protrusion 35a. A first spool spring (biasing member) 37a is provided in a compressed state between a first spring receiving portion 71a formed on one end side of the spring holder 70 and the first retainer 36a. The first spool 30a is urged by a first spool spring 37a in a direction that blocks communication between the supply port 61a and the main port 62a (the left direction in FIGS. 2 and 3).

  A second retainer 36b is fixed to the outer periphery at the center in the axial direction of the second spool 30b so as to come into contact with the protrusion 35b. A second spool spring (biasing member) 37b is provided in a compressed state between a second spring receiving portion 71b formed on the other end side of the spring holder 70 and the second retainer 36b. The second spool 30b is urged by the second spool spring 37b in a direction that blocks communication between the supply port 61b and the main port 62b (right direction in FIGS. 2 and 3).

  The first spool 30a is moved by the first solenoid 40a, and the second spool 30b is moved by the second solenoid 40b. The first solenoid 40a and the second solenoid 40b are proportional solenoids in which the plunger thrust (suction force) changes in proportion to the applied current value. The first solenoid 40a and the second solenoid 40b are attached to the second case member 52 so as to close the open end of the second accommodation hole 52a. The first solenoid 40a and the second solenoid 40b are each connected to a controller (not shown) via wiring.

  The first spool 30a moves against the reaction force of the first spool spring 37a by being pushed by the first plunger 41a of the first solenoid 40a. The second spool 30b moves against the reaction force of the second spool spring 37b by being pushed by the second plunger 41b of the second solenoid 40b.

  When the first solenoid 40a and the second solenoid 40b are not driven, the first spool 30a and the second spool 30b are located at the initial positions. At this time, the first spool 30a is stopped in a state where the protrusion 35a is in contact with the inner end surface of the first sleeve 60a, and the end surface of the first spool 30a and the tip of the first plunger 41a of the first solenoid 40a are Opposing each other with a predetermined interval (initial interval). The second spool 30b is stopped in a state where the projection 35b is in contact with the inner end surface of the second sleeve 60b, and the end surface of the second spool 30b and the tip of the second plunger 41b of the second solenoid 40b are predetermined. Are opposed to each other with an initial interval.

  As shown in FIGS. 1 and 4, the servo regulator 100 further includes a feedback link (feedback unit) 80 that transmits the displacement of the servo piston 20 to the spring holder 70. The feedback link 80 is rotatably supported by the first case member 51 via the support portion 91.

  The feedback link 80 extends between the servo piston 20 and the spring holder 70. Specifically, the first case member 51 is formed with a first insertion hole 51b that opens to the inner peripheral surface of the first accommodation hole 51a, and the second case member 52 has an inner circumference of the second accommodation hole 52a. A second insertion hole 52b that opens to the surface is formed. The first insertion hole 51b and the second insertion hole 52b are continuous, and the feedback link 80 extends between the servo piston 20 and the spring holder 70 through the first insertion hole 51b and the second insertion hole 52b. .

  The first end 81 of the feedback link 80 is inserted into the annular groove 24 of the servo piston 20. As a result, the feedback link 80 is connected to the servo piston 20.

  The first end 81 of the feedback link 80 is located on the opposite side of the slide metal 13 with respect to the central axis of the servo piston 20. The feedback link 80 extends in the tangential direction of the annular groove 24, and a part of the feedback link 80 is disposed in the annular groove 24 so as to cross the servo piston 20.

  The second end 82 of the feedback link 80 is connected to the spring holder 70. Specifically, an annular groove 74 is formed on the outer periphery of the spring holder 70, and the second end portion 82 is inserted into the annular groove 74.

  In this way, the feedback link 80 is connected to the servo piston 20 and to the spring holder 70. Since the servo piston 20 is connected to the swash plate 3 via the arm 10, the feedback link 80 is connected to the swash plate 3 via the servo piston 20 and the arm 10. Similarly, the spring holder 70 is connected to the swash plate 3 via the feedback link 80, the servo piston 20 and the arm 10.

  The feedback link 80 includes an intermediate portion 83 positioned between the first end portion 81 and the second end portion 82, a connecting portion 84 connecting the first end portion 81 and the intermediate portion 83, and a second end. A connecting portion 85 that connects the portion 82 and the intermediate portion 83. A center hole 83 a that passes through the center of rotation of the feedback link 80 is formed in the intermediate portion 83.

  As shown in FIGS. 1 and 5, the servo regulator 100 further includes a regulating member 90 that regulates the inclination of the feedback link 80 with respect to the rotation center axis. The restricting member 90 includes a support portion 91 that rotatably supports the feedback link 80, and a first shaft portion 92 and a second shaft portion that extend from the support portion 91 in opposite directions along the rotation center axis of the feedback link 80. A shaft portion 93.

  The support portion 91 is inserted into the center hole 83 a of the feedback link 80. The outer diameter of the support portion 91 is smaller than the outer diameter of the first shaft portion 92, and a step portion 94 is formed between the support portion 91 and the first shaft portion 92 (see FIG. 6). Since the step portion 94 faces the intermediate portion 83 of the feedback link 80, the step portion 94 regulates the inclination of the feedback link 80 toward the first shaft portion 92 side.

  The second shaft portion 93 is supported by the first case member 51 by insertion into the first hole 51e and the second hole 51f formed in the first case member 51. The first hole 51e opens to the inner peripheral surface of the first insertion hole 51b, and the second hole 51f opens to the bottom surface 51g of the first hole 51e. The first hole 51e and the second hole 51f are formed coaxially along the rotation center axis of the feedback link 80.

  A cylindrical bush 51h is disposed on the bottom surface 51g of the first hole 51e. The bush 51h has an outer diameter substantially equal to the inner diameter of the first hole 51e, and is fitted into the first hole 51e. The inner diameter of the bush 51h is substantially equal to the inner diameter of the second hole 51f. The outer diameter of the bush 51h may not be equal to the inner diameter of the first hole 51e as long as it can be inserted into the first hole 51e.

  The bush 51 h sandwiches the feedback link 80 between the step portion 94 of the regulating member 90 and regulates the inclination of the feedback link 80 toward the second shaft portion 93.

  Thus, the inclination of the feedback link 80 is regulated by the step portion 94 and the bush 51h of the regulating member 90. That is, the inclination of the feedback link 80 is regulated by the regulating member 90 that sandwiches the feedback link 80 with the first case member 51 via the bush 51h.

  In the servo regulator 100, the bush 51h is formed separately from the first case member 51, but is not limited to this configuration. For example, the bush 51 h may be formed integrally with the first case member 51, and the inclination of the feedback link 80 may be regulated by the bush 51 h integrated with the first case member 51 and the regulating member 90.

  The first shaft portion 92 is supported by the first case member 51 by being inserted into a hole 51 c formed in the first case member 51. The hole 51c penetrates between the outer surface of the first case member 51 and the inner peripheral surface of the first insertion hole 51b along the rotation center axis of the feedback link 80, and the first hole 51e and the second hole 51f. It is formed coaxially.

  Since the first hole 51e and the second hole 51f are formed coaxially with the hole 51c, even when the second shaft portion 93 is inserted into the first hole 51e and the second hole 51f, the regulating member 90 can be used as a feedback link. It can be moved in the direction of 80 rotation center axis. That is, the regulating member 90 is supported by the first case member 51 so as to be movable in the direction of the rotation center axis of the feedback link 80.

  When the regulating member 90 is moved relative to the first case member 51, the distance between the bush 51h and the stepped portion 94 of the regulating member 90 changes. Therefore, a desired interval can be provided between the bush 51 h and the step portion 94 of the regulating member 90 regardless of the forming accuracy of the feedback link 80 and the regulating member 90. Therefore, an interval that can regulate the inclination of the feedback link 80 without causing friction in the feedback link 80 can be provided between the bush 51 h and the step portion 94 of the regulating member 90.

  Thus, in the servo regulator 100, the friction of the feedback link 80 can be reduced while reducing the inclination of the feedback link 80 without strictly managing the dimensional tolerances such as the thickness of the feedback link 80. Therefore, the control characteristics of the servo regulator 100 can be easily improved.

  The second shaft portion 93 of the restriction member 90 has a male screw 93 a that is screwed into the second hole 51 f of the first case member 51. The restriction member 90 moves according to the amount of rotation with respect to the first case member 51 by screwing the male screw 93a and the second hole 51f. Specifically, when the regulating member 90 is rotated once with respect to the first case member 51, the regulating member 90 moves relative to the first case member 51 by one pitch of the male screw 93a.

  Since the regulating member 90 moves according to the amount of rotation with respect to the first case member 51, the amount of movement of the regulating member 90 with respect to the first case member 51 is controlled by managing the amount of rotation of the regulating member 90 with respect to the first case member 51. Can be managed. Therefore, the distance between the bush 51h and the step portion 94 of the regulating member 90 can be easily managed.

  When setting the interval between the bush 51h and the step portion 94 of the restricting member 90, first, the restricting member 90 is screwed into the first case member 51, and the feedback link 80 is pressed against the bush 51h by the step portion 94. Thereafter, the regulating member 90 is rotated and rotated by a predetermined amount in the opposite direction, and the regulating member 90 is moved in a direction in which the stepped portion 94 is separated from the bush 51h. As a result, the distance between the bush 51h and the step portion 94 of the regulating member 90 becomes larger than the thickness of the feedback link 80, and the friction of the feedback link 80 is reduced.

  Thus, by rotating the regulating member 90 to the first case member 51, a desired interval corresponding to the thickness of the feedback link 80 can be provided between the bush 51 h and the regulating member 90.

  The first shaft portion 92 protrudes outside the first case member 51 from the hole 51c. A male screw 92 a is formed on the outer periphery of the first shaft portion 92, and a fixing nut (fixing member) 96 is screwed into the male screw 92 a of the first shaft portion 92. The restriction member 90 is fixed to the first case member 51 by tightening the fixing nut 96 in a state where the second hole 51f and the second shaft portion 93 are screwed together.

  By fixing the restriction member 90 to the first case member 51 using the fixing nut 96, the rotation of the restriction member 90 relative to the first case member 51 can be prevented. The movement of the restricting member 90 with respect to the first case member 51 can be prevented, and the interval between the bush 51h and the step portion 94 of the restricting member 90 can be prevented from changing. Therefore, the inclination of the feedback link 80 and the change in the friction of the feedback link 80 can be reduced, and the control characteristics of the servo regulator 100 can be improved.

  As shown in FIGS. 5 and 6, the first shaft portion 92 and the second shaft portion 93 of the restricting member 90 are formed coaxially, while the support portion 91 includes the first shaft portion 92 and the second shaft portion 93. Is formed eccentrically. That is, the support portion 91 is eccentric with respect to the rotation center axis of the regulating member 90. Therefore, when the regulating member 90 is rotated with respect to the first case member 51, the center of the support portion 91 is displaced. As a result, the center of the center hole 83a of the feedback link 80, that is, the rotation center axis of the feedback link 80 is displaced.

  As shown in FIG. 4, the feedback link 80 is connected to the servo piston 20 and the spring holder 70. Therefore, the servo piston 20 and the spring holder 70 are displaced with the displacement of the rotation center of the feedback link 80.

  The spring constants of the first piston spring 59a and the second piston spring 59b (see FIG. 2) are larger than the spring constants of the first spool spring 37a and the second spool spring 37b (see FIG. 3) held by the spring holder 70. . Therefore, the displacement amount of the servo piston 20 is smaller than the displacement amount of the spring holder 70. That is, the displacement of the rotation center of the feedback link 80 mainly displaces the spring holder 70. Due to the displacement of the spring holder 70, the first spool spring 37a and the second spool spring 37b move, and the neutral positions of the first spool 30a and the second spool 30b change.

  Thus, in the servo regulator 100, the neutral position of the first spool 30a and the second spool 30b can be adjusted by rotating the regulating member 90. Since the adjustment of the neutral position is completed when the regulating member 90 is rotated at most half, the change in the distance between the bush 51h and the stepped portion 94 of the regulating member 90 accompanying the adjustment of the neutral position is within the half pitch of the male screw 93a. It is. That is, even when the neutral position is adjusted by rotating the regulating member 90, the interval between the bush 51h and the stepped portion 94 of the regulating member 90 is set within a range within a half pitch of the male screw 93a from the desired value. can do.

  In the restriction member 90, both the first shaft portion 92 and the second shaft portion 93 are supported by the first case member 51, and the support portion 91 connects the first shaft portion 92 and the second shaft portion 93. . That is, the regulating member 90 is supported at both ends by the first case member 51. Therefore, deformation of the restricting member 90 can be reduced. Therefore, it is possible to reduce the inclination of the feedback link 80 and reduce the friction caused by the inclination. As a result, the control characteristics of the servo regulator 100 are improved.

  The outer diameter of the second shaft portion 93 is smaller than the outer diameter of the first shaft portion 92. Therefore, the pitch of the male screw 93a of the second shaft portion 93 can be easily reduced as compared with the pitch of the male screw 92a of the first shaft portion 92. By reducing the pitch of the male threads 93a, the amount of movement of the regulating member 90 per rotation is reduced. Accordingly, even when the neutral position of the first spool 30a and the second spool 30b is adjusted by rotating the regulating member 90, the distance between the bush 51h and the step portion 94 of the regulating member 90 is within a narrower range. Can be set.

  Next, the operation of the servo regulator 100 will be described with reference to FIGS.

  When the driver operates the control lever of the vehicle to reverse the vehicle, a current corresponding to the operation amount of the control lever is applied to the first solenoid 40a, and the first plunger 41a of the first solenoid 40a is in the initial position. One spool 30a is moved (see FIG. 7).

  As shown in FIGS. 2 and 7, when the first spool 30a is moved by the first plunger 41a, the annular groove 33a of the first spool 30a connects the supply port 61a and the main port 62a. The hydraulic oil discharged from the hydraulic pump 5 is guided to the first pressure chamber 54a through the supply port 61a, the annular groove 33a, the main port 62a, and the main passage 6a.

  At this time, the second solenoid 40b is not driven, and the thrust of the second solenoid 40b does not act on the second spool 30b. In this state, the main port 62b communicates with the annular groove 34b of the second spool 30b, and the pressure in the second pressure chamber 54b is guided to the annular groove 34b.

  Since the annular groove 34b always communicates with the drain passage 7b through the protrusion 35b and the second sleeve 60b, the main port 62b communicates with the drain passage 7b through the annular groove 34b. That is, the second spool 30b blocks the communication between the supply port 61b and the main port 62b, and connects the main port 62b and the drain passage 7b. Therefore, the tank pressure is guided to the second pressure chamber 54b through the drain passage 7b and the main port 62b.

  The pilot pressure is guided to the first pressure chamber 54a and the tank pressure is guided to the second pressure chamber 54b, so that the servo piston 20 is moved from the neutral position against the urging force of the first piston spring 59a and the second piston spring 59b. Move in the P1 direction. Since the slide metal 13 (see FIG. 1) is inserted into the annular groove 24 of the servo piston 20, the slide metal 13 (see FIG. 1) moves in the P1 direction, and the arm 10 rotates.

  As the arm 10 rotates, the swash plate 3 of the piston pump 1 tilts to one side, and the tilt angle of the swash plate 3 changes. As a result, hydraulic oil is supplied from the piston pump 1 to the traveling motor, and the traveling hydraulic motor reverses and the vehicle moves backward.

  As shown in FIG. 4, since the first end 81 of the feedback link 80 is inserted into the annular groove 24 of the servo piston 20, when the servo piston 20 moves in the P1 direction, the first end 81 moves in the P1 direction. Move to. The feedback link 80 is rotated by the movement of the first end portion 81, and the second end portion 82 of the feedback link 80 is moved. As a result, as shown in FIG. 7, the spring holder 70 compresses the first spool spring 37a, and the reaction force (biasing force) of the first spool spring 37a that attempts to return the first spool 30a to the initial position increases. .

  Thus, the feedback link 80 changes the urging force of the first spool spring 37a in accordance with the movement of the servo piston 20, that is, the change in the tilt angle of the swash plate 3.

  When the biasing force of the first spool spring 37a changes, the first spool 30a moves so that the biasing force of the first spool spring 37a and the thrust of the first plunger 41a of the first solenoid 40a are balanced. Thereby, the pressure in the first pressure chamber 54a is adjusted so as to keep the servo piston 20 at a desired position. As a result, the tilt angle of the swash plate 3 of the piston pump 1 is maintained at a desired angle.

  On the other hand, when the driver operates the control lever to advance the vehicle, a current corresponding to the operation amount of the control lever is applied to the second solenoid 40b, and the second plunger 41b of the second solenoid 40b causes the second spool 30b to move. Move.

  When the second spool 30b is moved by the second plunger 41b, the annular groove 33b of the second spool 30b connects the supply port 61b and the main port 62b. The hydraulic oil discharged from the hydraulic pump 5 is guided to the second pressure chamber 54b through the supply port 61b, the annular groove 33b, the main port 62b, and the main passage 6b.

  At this time, the first solenoid 40a is not driven, and the thrust of the first solenoid 40a does not act on the first spool 30a. In this state, the main port 62a communicates with the annular groove 34a of the first spool 30a, and the pressure of the first pressure chamber 54a is guided to the annular groove 34a.

  Since the annular groove 34a always communicates with the drain passage 7a through between the protrusion 35a and the first sleeve 60a, the main port 62a communicates with the drain passage 7a through the annular groove 34a. That is, the first spool 30a disconnects the communication between the supply port 61a and the main port 62a, while connecting the main port 62a and the drain passage 7a. Therefore, the tank pressure is guided to the first pressure chamber 54a through the drain passage 7a and the main port 62a.

  The pilot pressure is guided to the second pressure chamber 54b and the tank pressure is guided to the first pressure chamber 54a, so that the servo piston 20 resists the urging force of the first piston spring 59a and the second piston spring 59b. Move in the P2 direction from the neutral position. The slide metal 13 (see FIG. 1) moves in the P2 direction, and the arm 10 rotates. As a result, the swash plate 3 of the piston pump 1 tilts to the other, the traveling hydraulic motor rotates forward, and the vehicle moves forward.

  Since the first end 81 of the feedback link 80 is inserted into the annular groove 24 of the servo piston 20, when the servo piston 20 moves in the P2 direction, the first end 81 of the feedback link 80 moves in the P2 direction. . The feedback link 80 is rotated by the movement of the first end portion 81, and the second end portion 82 of the feedback link 80 is moved. As a result, the spring holder 70 compresses the second spool spring 37b, and the reaction force (biasing force) of the second spool spring 37b that attempts to return the second spool 30b to the initial position increases.

  The second spool 30b is moved by the urging force of the second spool spring 37b, and the pressure in the second pressure chamber 54b is adjusted so as to keep the servo piston 20 at a desired position. Thereby, the tilt angle of the swash plate 3 of the piston pump 1 is maintained at a desired angle.

  According to the servo regulator 100, the first spool 30a and the second spool 30b are driven by the first solenoid 40a and the second solenoid 40b, and the pressure in the first pressure chamber 54a and the second pressure chamber 54b is controlled, and the servo is controlled. The tilt of the swash plate 3 of the piston pump 1 can be controlled by changing the position of the piston 20.

  Next, a method for assembling the servo regulator 100 will be described with reference to FIGS. Here, a method of assembling the feedback link 80 to the first case member 51 will be mainly described.

  First, as shown in FIG. 8, the servo piston 20 is inserted into the first accommodation hole 51 a of the first case member 51, and the first case member 51 is attached to the housing 2 of the piston pump 1. Thereafter, the bush 51 h is disposed on the bottom surface 51 g of the first hole 51 e, and the feedback link 80 is inserted into the first insertion hole 51 b of the first case member 51. By inserting the first end portion 81 of the feedback link 80 into the annular groove 24 of the servo piston 20, the feedback link 80 is connected to the servo piston 20.

  At this time, since the feedback link 80 has only to be inserted into the annular groove 24, there is no need to match the circumferential position of the servo piston 20. Therefore, the feedback link 80 can be easily connected to the servo piston 20.

  Further, when the feedback link 80 is inserted into the annular groove 24, the feedback link 80 is moved along the tangential direction of the annular groove 24, and the feedback link 80 is inserted into the annular groove 24 so as to cross the servo piston 20. . The movement of the feedback link 80 is not limited by the bottom surface of the annular groove 24, and the feedback link 80 can be inserted until it contacts the inner peripheral surface of the first housing hole 51 a of the first case member 51. Therefore, the feedback link 80 and the servo piston 20 can be connected even if the dimensional accuracy of the feedback link 80 is low.

  Next, as shown in FIG. 9, the regulating member 90 is inserted into the hole 51 c of the first case member 51. At this time, the second shaft portion 93 is inserted into the center hole 83a of the feedback link 80 and is inserted into the bush 51h.

  Next, the second shaft portion 93 is screwed into the second hole 51f, and the male screw 93a of the second shaft portion 93 is screwed into the inner peripheral surface of the second hole 51f. As a result, the support portion 91 of the regulating member 90 moves toward the center hole 83a of the feedback link 80. As a result, the support portion 91 is inserted into the center hole 83a (see FIG. 5).

  The regulating member 90 is further screwed into the first case member 51, and the feedback link 80 is pressed against the bush 51h by the step portion 94. Thereafter, the regulating member 90 is rotated by a predetermined amount in the opposite direction. Thereby, an interval corresponding to the thickness of the feedback link 80 is provided between the bush 51 h and the regulating member 90.

  Next, in a state where the rotation of the regulating member 90 with respect to the first case member 51 is regulated, the fixing nut 96 is screwed into the male screw 92 a of the first shaft portion 92. Thereby, the regulating member 90 is fixed to the first case member 51.

  Next, the second case member 52 is attached to the first case member 51. At this time, the feedback link 80 is inserted into the second insertion hole 52 b of the second case member 52, and the second end 82 of the feedback link 80 is inserted into the annular groove 74 of the spring holder 70. Thereby, the feedback link 80 is connected to the spring holder 70 (see FIG. 1).

  Thus, the assembly of the servo regulator 100 to the piston pump 1 is completed. Here, although the feedback link 80 is assembled | attached to the 1st case member 51 attached to the housing 2 of the piston pump 1, it is not restricted to this form. For example, the first case member 51 may not be attached to the housing 2 of the piston pump 1 when the feedback link 80 is assembled to the first case member 51.

  When adjusting the neutral position of the first spool 30a and the second spool 30b, first, the fixing nut 96 is loosened. Thereafter, the regulating member 90 is rotated with respect to the first case member 51 within a half rotation. Thereafter, the fixing nut 96 is screwed into the male screw 92 a of the first shaft portion 92 in a state where the rotation of the restricting member 90 with respect to the first case member 51 is restricted. Thereby, the regulating member 90 is fixed to the first case member 51 in a state where the neutral positions of the first spool 30a and the second spool 30b are adjusted.

  According to the above 1st Embodiment, there exists an effect shown below.

  The restriction member 90 is supported by the first case member 51 so as to be movable in the direction of the rotation center axis of the feedback link 80. Therefore, by moving the restricting member 90 relative to the first case member 51, the distance between the step 94 of the restricting member 90 and the bush 51h of the first case member 51 can be changed. Therefore, regardless of the forming accuracy of the feedback link 80 and the regulating member 90, the friction of the feedback link 80 can be reduced while regulating the inclination of the feedback link 80. As a result, the control characteristics of the servo regulator 100 are improved.

  Further, the male screw 93 a of the second shaft portion 93 of the restricting member 90 is screwed into the inner peripheral surface of the second hole 51 f of the first case member 51. for that reason. The restriction member 90 moves relative to the first case member 51 by rotation, and the position of the restriction member 90 with respect to the first case member 51 changes according to the amount of rotation of the restriction member 90. Therefore, the amount of movement of the regulating member 90 can be easily managed, and the distance between the stepped portion 64 of the regulating member 90 and the bush 51h of the first case member 51 can be easily managed. As a result, the control characteristics of the servo regulator 100 can be improved.

  Further, since the support portion 91 of the restriction member 90 is eccentric with respect to the rotation center axis of the restriction member 90, the rotation center axis of the feedback link 80 is displaced according to the rotation of the restriction member 90. Therefore, the neutral position of the first spool 30a and the second spool 30b can be adjusted by rotating the regulating member 90. Adjustment of the neutral position of the first spool 30a and the second spool 30b is completed when the restricting member 90 is rotated halfway at the maximum. For this reason, even when the neutral position is adjusted by rotating the regulating member 90, the distance between the bush 51h and the step portion 94 of the regulating member 90 is set within a range from a desired value to within a half pitch of the male screw 93a. can do.

  The regulating member 90 is supported at both ends by the first case member 51 by the first shaft portion 92 and the second shaft portion 93. Therefore, deformation of the restricting member 90 can be reduced. Therefore, it is possible to reduce the inclination of the feedback link 80 and reduce the friction caused by the inclination. As a result, the control characteristics of the servo regulator 100 are improved.

  Further, the outer diameter of the second shaft portion 93 is smaller than the outer diameter of the first shaft portion 92. Therefore, the pitch of the male screw 93a of the second shaft portion 93 can be easily reduced as compared with the pitch of the male screw 92a of the first shaft portion 92. By reducing the pitch of the male threads 93a, the amount of movement of the regulating member 90 per rotation is reduced. Accordingly, even when the neutral position of the first spool 30a and the second spool 30b is adjusted by rotating the regulating member 90, the distance between the bush 51h and the step portion 94 of the regulating member 90 is within a narrower range. Can be set.

Second Embodiment
Next, a servo regulator 200 according to a second embodiment of the present invention will be described with reference to FIG. The same components as those of the servo regulator 100 according to the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As illustrated in FIG. 10, the regulating member 290 of the servo regulator 200 includes a support portion 91 and a shaft portion 292. The restriction member 290 is not formed with a portion corresponding to the second shaft portion 93 (see FIG. 5 and the like) of the restriction member 90 according to the first embodiment. The first case member 251 is formed with a protrusion 251h protruding from the inner peripheral surface of the first insertion hole 51b, and the regulating member 290 is inclined with the feedback link 80 between the protrusion 251h and the inclination of the feedback link 80. To regulate.

  The shaft portion 292 is inserted into the hole 251c of the first case member 251 and is movably supported by the first case member 251. Therefore, regardless of the forming accuracy of the feedback link 80 and the regulating member 290, a desired interval can be provided between the protrusion 251h of the first case member 251 and the step portion 94 of the regulating member 290. Therefore, an interval that can regulate the inclination of the feedback link 80 without causing friction in the feedback link 80 can be provided between the protrusion 251 h and the step portion 94 of the regulating member 290.

  As described above, in the servo regulator 200 as well as the servo regulator 100, the friction of the feedback link 80 is reduced while reducing the inclination of the feedback link 80 without strictly managing the dimensional tolerance such as the thickness of the feedback link 80. be able to. Therefore, the control characteristics of the servo regulator 200 can be easily improved.

  The shaft portion 292 of the regulating member 290 has a male screw 292 a that is screwed into the hole 251 c of the first case member 251. The restriction member 290 moves according to the amount of rotation with respect to the first case member 251 by screwing the male screw 292a and the hole 251c. Specifically, when the regulating member 290 is rotated once with respect to the first case member 251, the regulating member 290 moves with respect to the first case member 251 by one pitch of the male screw 292a.

  Since the regulating member 290 moves according to the amount of rotation with respect to the first case member 251, the amount of movement of the regulating member 290 relative to the first case member 251 is controlled by managing the amount of rotation of the regulating member 290 with respect to the first case member 251. Can be managed. Therefore, the distance between the protrusion 251h and the step portion 94 of the restricting member 290 can be easily managed.

  The hole 251c opens on the outer surface of the first case member 251. Therefore, when forming the female screw on the inner peripheral surface of the hole 251c, it is easy to put the jig into the hole 251c, and the coaxiality of the female screw can be easily secured. Therefore, the inclination of the regulating member 290 caused by the inclination of the female screw can be prevented, and the inclination of the feedback link 80 can be prevented. As a result, the control characteristics of the servo regulator 200 are improved.

  Further, the fixing nut 96 is screwed into the male screw 292 a of the shaft portion 292. Therefore, it is not necessary to form a male screw different from the male screw 292a on the outer periphery of the regulating member 290, and the regulating member 290 can be easily manufactured. Therefore, the servo regulator 200 can be easily manufactured.

<Third Embodiment>
Next, a servo regulator 300 according to a third embodiment of the present invention will be described with reference to FIG. The same components as those of the servo regulator 100 and the servo regulator 200 are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 11, the regulating member 390 of the servo regulator 300 has a shaft portion 392. The restriction member 390 is not formed with the support portion 91 and the second shaft portion 93 (see FIG. 5 and the like) of the restriction member 90 according to the first embodiment, and the end surface 394 of the shaft portion 392 faces the feedback link 80. To do.

  The first case member 351 has a protrusion 351h that protrudes from the inner peripheral surface of the first insertion hole 51b, and a support 351m that is inserted into the center hole 83a of the feedback link 80 is formed at the tip of the protrusion 351h. Is done.

  A step portion 351n is formed between the protrusion 351h and the support portion 351m. The regulating member 390 regulates the inclination of the feedback link 80 with the feedback link 80 interposed between the regulating member 390 and the step portion 351n.

  The regulating member 390 is inserted into the hole 351c of the first case member 351, and is supported by the first case member 351 so as to be movable. Therefore, regardless of the forming accuracy of the feedback link 80 and the regulating member 390, a desired interval can be provided between the step portion 351n of the first case member 351 and the end surface 394 of the regulating member 390. Therefore, an interval that can regulate the inclination of the feedback link 80 without causing friction in the feedback link 80 can be provided between the step portion 351n of the first case member 351 and the end surface 394 of the regulating member 390.

  As described above, in the servo regulator 300, as in the servo regulators 100 and 200, the friction of the feedback link 80 is reduced while reducing the inclination of the feedback link 80 without strictly managing the dimensional tolerance such as the thickness of the feedback link 80. Can be reduced. Therefore, the control characteristics of the servo regulator 300 can be easily improved.

  The shaft portion 392 of the restriction member 390 has a male screw 392a that is screwed into the hole 351c of the first case member 351. The restriction member 390 moves according to the amount of rotation with respect to the first case member 351 by screwing the male screw 392a and the hole 351c. Specifically, when the regulating member 390 is rotated once with respect to the first case member 351, the regulating member 390 moves relative to the first case member 351 by one pitch of the male screw 392a.

  Since the regulating member 390 moves in accordance with the amount of rotation with respect to the first case member 351, the amount of movement of the regulating member 390 relative to the first case member 351 is controlled by managing the amount of rotation of the regulating member 390 relative to the first case member 351. Can be managed. Therefore, the distance between the step 351n of the first case member 351 and the end surface 394 of the restricting member 390 can be easily managed.

  In the servo regulator 300, the first case member 351 of the case 50 has a support portion 351m that is inserted into the center hole 83a and rotatably supports the feedback link 80. Therefore, the rotation center axis of the feedback link 80 is determined by the first case member 351. Therefore, the regulating member 390 can be rotated without displacing the rotation center axis of the feedback link 80 to change the distance between the first case member 351 and the regulating member 390, and the control characteristics of the servo regulator 300 can be easily achieved. Can be improved.

  Hereinafter, the configuration, operation, and effect of the embodiment of the present invention will be described together.

  The servo regulators 100, 200, and 300 include a servo piston 20 slidably accommodated in the first case members 51, 251 and 351, a first pressure chamber 54a provided facing the end of the servo piston 20, and A first pressure chamber 54b, a first spool 30a and a second spool 30b which are moved by the first solenoid 40a and the second solenoid 40b to control the pressure in the first pressure chamber 54a and the second pressure chamber 54b; The first spool spring 37a and the second spool spring 37b that urge the first spool 30a and the second spool 30b against the thrust of the solenoid 40a and the second solenoid 40b, and rotate according to the movement of the servo piston 20. Feedback for changing the urging force of the first spool spring 37a and the second spool spring 37b. The link 80 is supported by the first case members 51, 251 and 351 so as to be movable in the direction of the rotation center axis of the feedback link 80, and the feedback is provided with the feedback link 80 interposed between the first case members 51, 251 and 351. Restriction members 90, 290, 390 for restricting the inclination of the link 80.

  In this configuration, the restriction members 90, 290, 390 are supported by the first case members 51, 251, 351 so as to be movable in the direction of the rotation center axis of the feedback link 80. Therefore, by moving the restriction members 90, 290, 390 relative to the first case members 51, 251, 351, the distance between the restriction members 90, 290, 390 and the first case members 51, 251, 351 is changed. be able to. Therefore, the friction of the feedback link 80 can be reduced while regulating the inclination of the feedback link 80 regardless of the forming accuracy of the feedback link 80 and the regulating members 90, 290, and 390. As a result, the control characteristics of the servo regulators 100, 200, 300 are improved.

  In addition, the regulating members 90, 290, 390 are screwed into the first case members 51, 251, 351 and move in the direction of the rotation center axis according to the amount of rotation with respect to the first case members 51, 251, 351.

  In this configuration, the restriction members 90, 290, 390 are screwed into the first case members 51, 251, 351 and move relative to the first case members 51, 251, 351 according to the amount of rotation. , 290, 390 can be easily managed. Therefore, the distance between the regulating members 90, 290 and 390 and the first case members 51, 251 and 351 can be easily managed, and the control characteristics of the servo regulators 100, 200 and 300 can be improved.

  The feedback link 80 has a center hole 83a that passes through the center of rotation, and the regulating members 90 and 290 have support portions 91 that are inserted into the center hole 83a and support the feedback link 80 in a freely rotatable manner. The support portion 91 is eccentric with respect to the rotation center axis of the regulating members 90 and 290.

  In this configuration, since the support portion 91 is eccentric with respect to the rotation center axis of the restriction members 90 and 290, the rotation center axis of the feedback link 80 is displaced according to the rotation of the restriction members 90 and 290. Since the feedback link 80 changes the urging force of the first spool spring 37a and the second spool spring 37b, the neutral position of the first spool 30a and the second spool 30b can be adjusted by the displacement of the rotation center axis. Further, since the adjustment of the neutral position is completed when the regulating members 90 and 290 are rotated halfway at the maximum, the distance between the first case members 51 and 251 and the regulating members 90 and 290 is set to a half pitch of the screw from a desired value. It can be set within the range.

  The feedback link 80 has a center hole 83a that passes through the center of rotation, and the first case member 351 has a support portion 351m that is inserted into the center hole 83a and supports the feedback link 80 in a freely rotatable manner.

  In this configuration, the first case member 351 has a support portion 351m that is inserted into the center hole 83a and rotatably supports the feedback link 80. Therefore, the rotation center axis of the feedback link 80 is determined by the first case member 351. Therefore, the regulating member 390 can be rotated without displacing the rotation center axis of the feedback link 80 to change the distance between the first case member 351 and the regulating member 390, and the control characteristics of the servo regulator 300 can be easily achieved. Can be improved.

  The restricting member 90 extends from the support portion 91 along the rotation center axis of the feedback link 80 and is supported by the first case member 51, and is opposite to the first shaft portion 92. And a second shaft portion 93 extending from the support portion 91 and supported by the first case member 51.

  In this configuration, both the first shaft portion 92 and the second shaft portion 93 are supported by the first case member 51, and the regulating member 90 is both-end supported by the first case member 51. Therefore, deformation of the restricting member 90 can be reduced. Therefore, it is possible to reduce the inclination of the feedback link 80 and reduce the friction caused by the inclination. As a result, the control characteristics of the servo regulator 100 are improved.

  The second shaft portion 93 has an outer diameter smaller than the outer diameter of the first shaft portion 92 and is screwed with the first case member 51.

  In this configuration, the second shaft portion 93 having an outer diameter smaller than the outer diameter of the first shaft portion 92 is screwed into the first case member 51. Therefore, the pitch of the male screw can be reduced, and the amount of movement of the regulating member 90 per rotation can be reduced. Therefore, even when the neutral position of the first spool 30a and the second spool 30b is adjusted by rotating the regulating member 90, the interval between the first case member 51 and the regulating member 90 is set within a narrower range. can do.

  In addition, the regulating members 290 and 390 are screwed into the inner peripheral surfaces of the holes 251c and 351c that open to the outer side surfaces of the first case members 251 and 351.

  In this configuration, the restriction members 290 and 390 are screwed into the inner peripheral surfaces of the holes 251c and 351c that open to the outer side surfaces of the first case members 251 and 351. Therefore, when forming the female screw on the inner peripheral surface of the holes 251c and 351c, it is easy to put the jig into the holes 251c and 351c, and the coaxiality of the female screw can be easily secured. Therefore, the inclination of the regulating members 290 and 390 due to the inclination of the female screw can be prevented, and the inclination of the feedback link 80 can be prevented. As a result, the control characteristics of the servo regulators 200 and 300 are improved.

  The servo regulators 200 and 300 further include a fixing nut 96 that is screwed with the restricting members 290 and 390 to fix the restricting members 290 and 390 to the first case members 251 and 351, and the restricting members 290 and 390 have holes 251c. , 351 c and male threads 292 a and 392 a which are screwed into the fixing nut 96.

  In this configuration, the male screws 292a and 392a of the regulating members 290 and 390 are screwed with the inner peripheral surfaces of the holes 251c and 351c and are screwed with the fixing nut 96. Therefore, it is only necessary to form one type of male screw on the regulating members 290 and 390, and the regulating members 290 and 390 can be easily manufactured. Therefore, the servo regulators 200 and 300 can be easily manufactured.

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

  100, 200, 300 ... servo regulator, 20 ... servo piston, 30a ... first spool (spool), 30b ... second spool (spool), 37a ... first spool spring (with) 37b ... second spool spring (biasing member), 40a ... first solenoid (solenoid), 40b ... second solenoid (solenoid), 51,251,351 ... first Case member (case), 54a ... 1st pressure chamber (pressure chamber), 54b ... 2nd pressure chamber (pressure chamber), 80 ... Feedback link (feedback part), 83a ... Center hole, 90, 290, 390... Restricting member, 91... Support portion, 92... First shaft portion, 93. a, 392a ··· male thread, 351m ··· support section

Claims (8)

A servo regulator,
A servo piston slidably housed in the case;
A pressure chamber provided facing the end of the servo piston;
A spool that is moved by a solenoid to control the pressure in the pressure chamber;
A biasing member that biases the spool against the thrust of the solenoid;
A feedback unit that rotates according to the movement of the servo piston to change the urging force of the urging member;
And a regulating member that is supported by the case so as to be movable in the direction of the rotation center axis of the feedback unit, and that regulates the inclination of the feedback unit with the feedback unit sandwiched between the case and the case. Servo regulator. The servo regulator according to claim 1,
The servo regulator is characterized in that the regulating member is screwed with the case and moves in the direction of the rotation center axis in accordance with an amount of rotation with respect to the case. The servo regulator according to claim 2,
The feedback unit has a center hole that passes through the rotation center,
The restriction member has a support portion that is inserted into the center hole and rotatably supports the feedback portion,
The servo regulator according to claim 1, wherein the support portion is eccentric with respect to a rotation center axis of the restriction member. The servo regulator according to claim 2,
The feedback unit has a center hole that passes through the rotation center,
The servo regulator according to claim 1, wherein the case includes a support portion that is inserted into the center hole and rotatably supports the feedback portion. The servo regulator according to claim 3, wherein
The regulating member is
A first shaft portion extending from the support portion along the rotation center axis of the feedback portion and supported by the case;
The servo regulator further comprising: a second shaft portion that extends from the support portion and is supported by the case on a side opposite to the first shaft portion. The servo regulator according to claim 5, wherein
The servo regulator according to claim 1, wherein the second shaft portion has an outer diameter smaller than that of the first shaft portion and is screwed into the case. The servo regulator according to any one of claims 2 to 6,
The servo regulator according to claim 1, wherein the restricting member is screwed into an inner peripheral surface of a hole opened in an outer surface of the case. The servo regulator according to claim 7, wherein
A fixing member that is screwed with the restricting member and fixes the restricting member to the case;
The said regulator is a servo regulator characterized by having a male screw screwed together with the internal peripheral surface of the said hole, and screwed together with the said fixing member.

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