JP6668267B2 - Oblique axis type hydraulic rotary machine - Google Patents

Description

  The present invention relates to a diagonal hydraulic rotary machine mounted on a construction machine such as a hydraulic shovel or a hydraulic crane and used as a hydraulic pump or a hydraulic motor.

  In general, a variable-capacity oblique-shaft hydraulic rotary machine is provided with a hollow casing body in which one side in the axial direction serves as a bearing, and an opening on the other side in the axial direction of the casing body which is provided in an arc shape. A head casing having a concave concave arc-shaped sliding contact portion, a rotary shaft rotatably provided on a bearing portion of the casing main body, and a tip end on the insertion side into the casing main body serving as a drive disk, and provided on the casing main body. A plurality of cylinders extending in the axial direction are arranged at intervals in the circumferential direction and the other end surface in the axial direction is a sliding contact end surface, and one end side is swingably connected to the rotation center position of the drive disk of the rotating shaft. The other end is reciprocally fitted to the center shaft inserted into the center cylinder of the cylinder block and each cylinder of the cylinder block, and one end swings to the drive disk. A plurality of pistons are connected between the head casing and the cylinder block so that one end surface is in sliding contact with the sliding end surface of the cylinder block, and the other end surface is inclined to the concave arc-shaped sliding contact portion of the head casing. The valve plate is a convex arcuate sliding contact portion that slides as much as possible, and a servo pin provided on the head casing and extending from the servo piston for tilting the valve plate together with the cylinder block toward the valve plate is fitted into the valve plate. And a tilting mechanism connected to the hole (see, for example, Patent Document 1).

  On the other hand, as a constant-capacity oblique-axis hydraulic rotating machine, there is known a configuration in which a guide hole is provided in a head casing and a center hole is provided in a center shaft, and the guide hole and the center hole are positioned with a guide rod. (For example, see Patent Document 2).

JP 2000-303961 A JP-A-7-54767

  By the way, when assembling the head casing to the casing main body, it is necessary to fit two places. That is, it is necessary to perform fitting between the side surface of the concave arc-shaped sliding contact portion of the head casing and the side surface of the convex arc-shaped sliding contact portion of the valve plate, and fitting between the distal end side of the servo pin and the fitting hole of the valve plate. There is.

  According to the above-mentioned Patent Document 1, after the side surface of the concave arc-shaped sliding contact portion of the head casing and the side surface of the convex arc-shaped sliding contact portion of the valve plate are fitted, the leading end side of the servo pin and the fitting hole of the valve plate are fitted. Are fitted. In this case, since the side surface of the concave arc-shaped sliding contact portion of the head casing and the side surface of the convex arc-shaped sliding contact portion of the valve plate are fitted first, the distal end side of the servo pin and the fitting hole of the valve plate are fitted. It is difficult to visually see the outside. As a result, it may be troublesome to fit the distal end side of the servo pin and the fitting hole of the valve plate.

  On the other hand, it is conceivable to adopt a configuration in which a head casing is attached to a casing main body using a guide rod as described in Patent Document 2 described above in a variable displacement type oblique-axis hydraulic rotary machine. However, in this case, since a step of forming a guide hole in the head casing and a step of closing the guide hole are required, the number of processing steps increases, and the cost may increase. In addition, since parts for closing the guide holes are required, the number of parts may increase. Further, a space for providing a guide hole in the head casing is required, and the head casing may be increased in size.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the related art, and an object of the present invention is to provide an oblique-axis hydraulic rotary machine that enables a head casing to be easily assembled to a casing main body. is there.

  An oblique-axis hydraulic rotating machine according to the present invention includes a head casing having a concave arc-shaped sliding contact portion provided by closing an axial opening of a casing body and concaved in an arc shape, and the head casing and a cylinder block. A valve plate having a convex arc-shaped sliding contact portion provided between the two ends, one end surface of which is in sliding contact with the sliding contact end surface of the cylinder block, and the other end surface of which is in sliding contact with the concave arc-shaped sliding contact portion of the head casing. A tilting mechanism provided on the head casing and having a servo pin extending toward the valve plate from a servo piston for tilting the valve plate together with the cylinder block connected to a fitting hole of the valve plate; Is provided.

In order to solve the above-described problem, a feature of the configuration adopted by the present invention is that the valve plate and the head casing are separated from each other in a central axis direction of the servo pin, and a concave arc-shaped sliding contact portion of the head casing is provided. When the convex arc-shaped sliding contact portion of the valve plate is opposed to the convex arc-shaped sliding contact portion of the valve plate, the edge of the side surface of the concave arc-shaped sliding contact portion of the head casing and the convex arc-shaped sliding contact portion of the valve plate. When the distance in the axial direction from the edge of the side surface is A, and the distance in the axial direction between the tip of the servo pin and the fitting hole of the valve plate is B, at least one position in the tilt range of the valve plate. A> B is set , and a spherical fitting portion is provided at the tip of the servo pin on the valve plate side, and a tapered guide portion tapering to the tip end side from the fitting portion is formed. And the center of the guide portion and the servo pin The angle (α) between the line (KK) and the center axis (L−L) of the valve plate when the valve plate is tilted to the maximum and the center axis (K−K) of the servo pin are determined. The angle (β) that is larger than the angle (β) and the angle (L−L) between the center axis (L−L) of the valve plate and the center axis (K−K) of the servo pin when the valve plate is tilted to the minimum. γ) .

  According to the present invention, the head casing can be easily assembled to the casing main body.

1 is a cross-sectional view showing a variable displacement oblique shaft type hydraulic pump according to an embodiment of the present invention in a maximum tilt state. FIG. 2 is a cross-sectional view illustrating a state where the head casing in FIG. 1 is assembled to a casing main body. FIG. 3 is an enlarged view of a part III in FIG. 2. FIG. 3 is a cross-sectional view of the same position as FIG. 2 showing a state in which a distal end side of a servo pin is fitted into a fitting hole of a valve plate. It is sectional drawing seen from the arrow VV direction in FIG. FIG. 6 is a cross-sectional view of the same position as FIG. 5 showing a state in which the distal end side of a servo pin is fitted into a fitting hole of a valve plate. It is a side view which shows a servo pin by itself. FIG. 7 is a cross-sectional view showing an intermediate state between a maximum tilt and a minimum tilt (a state in which the center axis of the valve plate coincides with the center axis of the servo pin). It is sectional drawing which shows a minimum tilting state.

  Hereinafter, as the oblique-axis hydraulic rotating machine according to the embodiment of the present invention, a variable-capacity oblique-axis hydraulic rotating machine, more specifically, a variable-capacity oblique-axis hydraulic pump as an example, This hydraulic pump will be described in detail with reference to FIGS.

  In FIG. 1, a variable-capacity oblique-axis hydraulic pump (hereinafter, referred to as a hydraulic pump 1) serving as an oblique-axis hydraulic rotary machine is rotationally driven by, for example, a motor of a hydraulic shovel, and sucks oil from a hydraulic oil tank. Thus, pressure oil is supplied to various hydraulic devices (none shown) connected downstream of the hydraulic pipeline. The hydraulic pump 1 includes a casing body 2, a head casing 3, a rotating shaft 4, a cylinder block 6, a center shaft 7, a piston 8, a valve plate 9, a tilting mechanism 10, and the like.

  The casing body 2 is formed as a hollow cylindrical body that becomes the outer shell of the hydraulic pump 1. The casing body 2 includes a substantially cylindrical bearing portion 2A positioned on one side in the axial direction, and a cylinder block housing portion 2B that extends obliquely from the other end of the bearing portion 2A. I have. A head casing 3 is attached to the other end of the cylinder block housing 2B. That is, the casing main body 2 and the head casing 3 constitute a casing of the entire hydraulic pump 1.

  The head casing 3 is provided so as to close the opening on the other side in the axial direction of the casing main body 2, that is, the other end of the cylinder block housing portion 2B. The head casing 3 has a concave arc-shaped sliding contact portion 3B on one end surface 3A located on the casing body 2 side. On the other hand, the head casing 3 is provided with a cylinder hole 11 of a tilting mechanism 10 to be described later, which is located at a depth of the concave arc-shaped sliding contact portion 3B. Further, the head casing 3 is provided with a suction flow passage and a discharge flow passage (both not shown) opened to (the concave circular surface 3C of) the concave circular sliding contact portion 3B with the cylinder hole 11 interposed therebetween. I have.

  Here, the concave arc-shaped sliding contact portion 3B is concave in an arc shape. That is, the concave arc-shaped sliding contact portion 3B is a concave arc formed along a tilt radius (oscillation radius) when the valve plate 9 tilts (oscillates) with the center shaft 7 as a fulcrum (center of rotation). It has a surface 3C and side surfaces 3D located at both ends of the concave arc surface 3C and extending from the concave arc surface 3C toward the cylinder block 6 side. The convex arc-shaped sliding contact portion 9B of the valve plate 9 is fitted to the concave arc-shaped sliding contact portion 3B in a tiltable manner. That is, the concave arcuate surface 3C of the concave arcuate sliding contact portion 3B is in sliding contact with the convex circular surface 9C of the convex arcuate sliding contact portion 9B of the valve plate 9, and the side surface 3D of the concave arcuate sliding contact portion 3B is a valve plate. 9 is in sliding contact with the side surface 9D of the convex arc-shaped sliding contact portion 9B.

  The rotating shaft 4 is located in the bearing 2A of the casing main body 2 and extends in the bearing 2A in the axial direction. The rotating shaft 4 is rotatably supported in the bearing portion 2A via a plurality (for example, three) of bearings 5. One end of the rotating shaft 4 is a protruding end 4A that protrudes from the casing body 2 in the axial direction, and a motor such as an engine is connected to the protruding end 4A via a power transmission mechanism or the like (neither is shown). You. On the other hand, a disk-shaped drive disk 4B is formed on the rotating shaft 4 at the distal end on the insertion side into the casing body 2, that is, at the other end in the axial direction.

  The cylinder block 6 is provided in the cylinder block accommodating portion 2 </ b> B of the casing main body 2 so as to rotate integrally with the rotation shaft 4. The cylinder block 6 is formed as a cylindrical body, and has a center shaft insertion hole 6A as a center cylinder into which the center shaft 7 is inserted along the center axis. On the other hand, in the cylinder block 6, a plurality of cylinders 6B (only one is shown) which are located around the center shaft insertion hole 6A and extend in the axial direction are arranged at intervals in the circumferential direction. Further, in the cylinder block 6, the other end surface in the axial direction on the valve plate 9 side described later is a sliding contact end surface 6C. The sliding contact end surface 6C is in sliding contact with the switching surface 9A of the valve plate 9, and is formed in a concave spherical shape.

  The center shaft 7 is inserted into the center shaft insertion hole 6A of the cylinder block 6. The center shaft 7 supports the cylinder block 6 between the drive disk 4B of the rotating shaft 4 and the valve plate 9 so as to be tiltable. One end of the center shaft 7 is swingably connected to the rotation center position of the drive disk 4B of the rotary shaft 4, and the other end is inserted into the center shaft insertion hole 6A. The other end of the center shaft 7 is provided with a spring 7A. The spring 7A presses the cylinder block 6 against the valve plate 9.

  A plurality of pistons 8 are inserted into each cylinder 6B of the cylinder block 6 so as to be able to reciprocate. One end of each of the plurality of pistons 8 protruding from the cylinder 6B is swingably connected to the drive disk 4B of the rotary shaft 4. Each of the pistons 8 reciprocates in the cylinder 6B by rotating the cylinder block 6 tilted with respect to the rotation shaft 4, and performs suction and discharge of the oil liquid.

  The valve plate 9 is provided between the head casing 3 and the cylinder block 6. The valve plate 9 tilts along the concave arc surface 3C in the concave arc-shaped sliding contact portion 3B of the head casing 3. The valve plate 9 has a rectangular outer shape that fits within the width of the concave arc-shaped sliding contact portion 3B (dimension in the lateral direction with respect to the tilting direction, separation of the side surface 3D). On one end surface of the valve plate 9, there is provided a convex spherical switching surface 9 </ b> A which is in sliding contact with the sliding contact end surface 6 </ b> C of the cylinder block 6. On the other hand, on the other end surface of the valve plate 9 opposite to the switching surface 9A, a convex arc-shaped sliding contact portion 9B protruding with an arc corresponding to the concave arc-shaped sliding contact portion 3B of the head casing 3 is provided. The convex arc-shaped sliding contact portion 9B comes into sliding contact with the concave arc-shaped sliding contact portion 3B of the head casing 3 when the tilting mechanism 10 is operated.

  In this case, as shown in FIG. 5, the convex arc-shaped sliding contact portion 9B has a convex arc-shaped surface 9C protruding corresponding to the concave arc-shaped surface 3C of the concave arc-shaped sliding contact portion 3B, and both ends of the convex arc-shaped sliding surface 9C. Side faces 9D located at both ends of the valve plate 9). The convex arc-shaped sliding contact portion 9B is tiltably fitted to the concave arc-shaped sliding contact portion 3B.

  As shown in FIG. 3, the valve plate 9 is provided with a fitting hole 9E which is located at the center of the switching surface 9A and penetrates in the axial direction. The front end 13A of the servo pin 13 is inserted into the fitting hole 9E. A large-diameter portion 9F having an inner diameter larger than other portions of the fitting hole 9E is formed on the other end side (the head casing 3 side) of the fitting hole 9E. That is, the fitting hole 9E has, in order from the other end, a large-diameter portion 9F (a convex-arc-shaped sliding contact portion side), a small-diameter portion 9G, and a large-diameter portion 9H (a switching surface side). The fitting portion 13B of the servo pin 13 is fitted in the small diameter portion 9G of the fitting hole 9E. The fitting hole 9E facilitates the insertion of the tip 13A of the servo pin 13 into the fitting hole 9E by increasing the opening (insertion port) on the side where the servo pin 13 is inserted by the large diameter portion 9F.

  The tilting mechanism 10 is provided on the head casing 3. The tilting mechanism 10 tilts the valve plate 9 together with the cylinder block 6. The tilting mechanism 10 includes a cylinder hole 11 that is located deeper than the deepest portion of the concave arc-shaped sliding contact portion 3B and linearly extends in the tilting direction of the valve plate 9. A servo piston 12 as an operating portion slidably inserted therein, and provided at an intermediate portion in the longitudinal direction of the servo piston 12, protruding radially from the servo piston 12 and extending toward the valve plate 9. Servo pins 13. The cylinder hole 11 has a large-diameter hole 11A serving as a one-side cylinder hole and a small-diameter hole 11B serving as a second-side cylinder hole.

  The servo pin 13 has a proximal end inserted into a pin hole 12A formed in the servo piston 12 and a distal end 13A side inserted (connected) into a fitting hole 9E of the valve plate 9. That is, a fitting portion 13B such as a spherical joint is provided near the tip 13A of the servo pin 13 located on the valve plate 9 side, and the fitting portion 13B fits into (the small diameter portion 9G of) the fitting hole 9E. As a result, the servo pins 13 and the valve plate 9 are connected. A tapered (reduced-diameter) guide portion 13C that is tapered is formed at the tip 13A of the servo pin 13. In this case, as shown in FIG. 7, the angle between the central axis KK of the servo pin 13 and the (inclined surface) of the guide portion 13C is set to α.

  The tilting mechanism 10 moves the servo piston 12 along the cylinder holes 11 (11A, 11B) by supplying an oil liquid from the oil holes (not shown) into the cylinder holes 11 (11A, 11B). can do. Thus, by moving the servo piston 12, the valve plate 9 can be tilted together with the cylinder block 6 via the servo pins 13. Thereby, the tilt mechanism 10 adjusts the tilt angle of the cylinder block 6 and the valve plate 9 with respect to the rotation shaft 4 between the minimum tilt position shown in FIG. 9 and the maximum tilt position shown in FIG. Can be.

  The hydraulic pump 1 according to the present embodiment has the above-described configuration. Next, the operation of the hydraulic pump 1 will be described.

  First, the valve plate 9 is moved to the maximum tilt position shown in FIG. 1 together with the cylinder block 6 by the tilt mechanism 10. In this case, pressure oil from a pilot pump (not shown) is supplied into (the small-diameter hole 11B of) the cylinder hole 11, and the servo piston 12 is displaced. At this time, the valve plate 9 to which the servo pins 13 are connected tilts together with the cylinder block 6 and moves to the maximum tilt position.

  On the other hand, when the pressure oil is supplied from the oil passage hole into the cylinder hole 11 (the large-diameter hole 11A), the valve plate 9 is moved together with the cylinder block 6 in the minimum tilt position (the position shown in FIG. 9) or the maximum tilt position. It is possible to move to an intermediate position (the position shown in FIG. 8) between the shift position and the minimum tilt position. FIG. 8 shows a state where the valve plate 9 and the cylinder block 6 are in the intermediate position, that is, the angle between the central axis LL of the valve plate 9 and the central axis KK of the servo pin 13 is 0 (zero). Is shown.

  Next, when the rotary shaft 4 is driven to rotate by a prime mover (not shown) such as an engine or a motor, the cylinder block 6 rotates together with the drive disk 4B of the rotary shaft 4. At this time, as the cylinder block 6 rotates, the piston 8 reciprocates in each cylinder 6B. Here, in the suction stroke of the reciprocating piston 8, the oil liquid is sucked into the cylinder 6B from the hydraulic oil tank through the suction passage (not shown) of the head casing 3 or the like. Subsequently, in a discharge stroke of the piston 8, pressure oil is discharged from the cylinder 6B, and the pressure oil is supplied to various hydraulic devices connected to the downstream side of the hydraulic pipeline through a discharge flow path (not shown) of the head casing 3. (Neither is shown) can be supplied with pressurized oil.

  By the way, according to the related art, when assembling the head casing to the casing main body, it is necessary to fit the head casing and the valve plate, and then fit the distal end side of the servo pin and the fitting hole of the valve plate. is there. For this reason, the fitting operation for fitting the front end side of the servo pin and the fitting hole of the valve plate becomes difficult to visually recognize from the outside, and this fitting operation may be troublesome.

  Therefore, the present embodiment employs the following configuration. Hereinafter, as a characteristic portion of the present invention, the dimensional relationship (length relationship) between the concave arc-shaped sliding contact portion 3B of the head casing 3 and the convex arc-shaped sliding contact portion 9B of the valve plate 9 will be described in detail with reference to FIGS. State. In this case, as shown in FIG. 2, the dimensional relationship will be described based on the case where the head casing 3 is assembled to the casing main body 2. That is, the valve plate 9 and the head casing 3 are separated from each other in the central axis direction of the servo pin 13, and the concave arc-shaped sliding contact portion 3B of the head casing 3 and the convex arc-shaped sliding contact portion 9B of the valve plate 9 are arbitrarily fixed. Open and face to face. In this state, the dimensional relationship will be described with reference to the center axis direction of the servo pin 13. The dimensional relationship is regulated (defined) based on the axial direction of the servo pin 13, but may be regulated (defined) based on the vertical direction, for example.

  As shown in FIG. 2, the assembling work of assembling the head casing 3 to the casing main body 2 is performed by, for example, assembling the head casing 3 lifted using a crane or the like from above the casing main body 2. At this time, the servo casing 13 side of the head casing 3 is vertically downward, and the cylinder block 6 side of the casing body 2 is vertically upward. Further, the cylinder block 6, the valve plate 9, the servo piston 12, and the servo pin 13 are at the maximum tilt position due to gravity. At this time, as shown in FIG. 2, the cylinder block 6 and the valve plate 9 are pushed up by the spring 7A of the center shaft 7, and are in a state of approaching the servo pin 13 side.

  Here, as shown in FIG. 5, the tip 13A of the servo pin 13 protrudes toward the valve plate 9 from the edge 3D1 of the side surface 3D of the concave arc-shaped sliding contact portion 3B of the head casing 3. On this basis, as shown in FIGS. 3 and 5, the dimensional relationship of each part is regulated (defined) as follows. That is, the distance between the edge 3D1 of the side surface 3D of the concave arc-shaped sliding contact portion 3B of the head casing 3 and the edge 9D1 of the side surface 9D of the convex arc-shaped sliding contact portion 9B of the valve plate 9 is A, and the servo pin 13 B is the axial distance between the front end 13A and the fitting hole 9E of the valve plate 9. In this case, A and B represent at least one of the positions in the tilt range of the valve plate 9, more specifically, the position of the valve plate 9 at least at the maximum tilt, and the relationship expressed by the following equation (1). Is set to

  In this case, the axial distance B is, for example, set such that the concave arc-shaped sliding contact portion 3B and the convex arc-shaped sliding contact portion 9B face each other at an arbitrary constant interval in the axial direction of the servo pin 13. The shortest distance among the axial distances between the distal end 13A and the opening edge of the large-diameter portion 9F of the fitting hole 9E of the valve plate 9. That is, the axial distance B is, for example, a distance between a portion of the opening edge of the large diameter portion 9F of the fitting hole 9E, which is closest to the head casing 3, and the tip 13A of the servo pin 13.

  Further, since the large-diameter portion 9F is provided in the fitting hole 9E of the valve plate 9, when the length of the large-diameter portion 9F in the axial direction is C, the axial distances A, B, and C are: , And the following equation (2) is set.

  The axial distances A, B, and C satisfy the above equation (2). Therefore, when the head casing 3 is assembled to the casing main body 2 as shown in FIGS. Prior to the engagement between the side surface 3D of the contact portion 3B and the side surface 9D of the convex arc-shaped sliding contact portion 9B of the valve plate 9, the distal end 13A of the servo pin 13 and the fitting hole 9E of the valve plate 9 (small diameter portion 9G). Are fitted. That is, A> 0 when the distance between the tip of the servo pin 13 and the fitting hole 9E between the valve plate 9 is 0 (B + C = 0), so that the servo pin 13 and the fitting hole 9E between the valve plate 9 Can be fitted visually.

  Here, as shown in FIG. 7, when an angle formed between (the inclined surface of) the guide portion 13 </ b> C of the servo pin 13 and the center axis KK of the servo pin 13 is α, the angle α formed is as follows. You have set. That is, as shown in FIG. 1, the angle between the central axis LL of the valve plate 9 and the central axis KK of the servo pin 13 when the valve plate 9 is tilted to the maximum is β. Further, as shown in FIG. 9, the angle between the center axis LL of the valve plate 9 and the center axis KK of the servo pin 13 when the valve plate 9 is tilted to the minimum is defined as γ. In this case, the angle α is set to be larger than the angles β and γ. That is, the angles α, β, and γ are set in the relationship of the following equations (3) and (4).

  Thus, according to the present embodiment, the valve plate 9 and the head casing 3 are separated from each other in the direction of the center axis of the servo pin 13, and the concave arc-shaped sliding contact portion 3B of the head casing 3 and the convex arc-shaped sliding contact of the valve plate 9 are formed. When facing the portion 9B at an arbitrary fixed interval, the edge 3D1 of the side surface 3D of the concave arc-shaped sliding contact portion 3B of the head casing 3 and the side surface 9D of the convex arc-shaped sliding contact portion 9B of the valve plate 9 Is defined as A, and the axial distance between the tip 13A of the servo pin 13 and the fitting hole 9E of the valve plate 9 is defined as B. In this case, A> B is set at at least any position in the tilt range of the valve plate 9. Thereby, the head casing 3 can be easily assembled to the casing main body 2.

  That is, when the hydraulic pump 1 attaches the head casing 3 to the casing main body 2, after the servo pin 13 and the fitting hole 9 </ b> E of the valve plate 9 are fitted, the side surface 3D of the concave arc-shaped sliding contact portion 3 </ b> B of the head casing 3 is formed. And the side surface 9D of the convex arc-shaped sliding contact portion 9B of the valve plate 9 can be fitted. In other words, prior to the engagement between the side surface 3D of the concave arc-shaped sliding contact portion 3B of the head casing 3 and the side surface 9D of the convex arc-shaped sliding contact portion 9B of the valve plate 9, a fitting hole between the servo pin 13 and the valve plate 9 is formed. 9E can be fitted.

  Thereby, the operation of inserting (fitting) the tip 13A side of the servo pin 13 into the fitting hole 9E of the valve plate 9 can be performed while visually observing from the outside, so that the head casing 3 is easily assembled to the casing main body 2. be able to. Moreover, after the distal end 13A side of the servo pin 13 starts to be inserted (fitted) into the fitting hole 9E of the valve plate 9, the distal end 13A side of the servo pin 13 enters the back side while being guided by the fitting hole 9E. At this time, since the position of the valve plate 9 is regulated by the servo pin 13, the side surface 3D of the concave arc-shaped sliding contact portion 3B of the head casing 3 after the servo pin 13 is fitted into the fitting hole 9E and the valve plate. 9 can be easily fitted to the side surface 9D of the convex arc-shaped sliding contact portion 9B.

  Further, according to the present embodiment, A> B is set at least at the position of the maximum tilt in the tilt range of the valve plate 9. Thus, the work of fitting the servo pin 13 and the fitting hole 9E of the valve plate 9 can be performed in a state where the valve plate 9 and the like are at the maximum tilt position due to gravity. This makes it possible to omit (or facilitate) the operation of positioning the cylinder block 6 and the servo pins 13 in the tilting direction by using a jig or the like at the time of this fitting, and the casing main body 2 is also provided with this surface. The head casing 3 can be easily assembled.

  Further, according to the present embodiment, the fitting hole 9E of the valve plate 9 is formed with the large-diameter portion 9F having a larger inner diameter than other portions on the head casing 3 side. Thereby, when the servo pin 13 is fitted into the fitting hole 9E of the valve plate 9, the insertion hole of the fitting hole 9E is widened, so that the servo pin 13 is easily fitted into the fitting hole 9E of the valve plate 9. can do.

  Further, according to the present embodiment, after the large-diameter portion 9F is provided in the fitting hole 9E of the valve plate 9 and the length of the large-diameter portion 9F in the axial direction is C, A> B + C Is set to Thereby, the distance until the tip 13A of the servo pin 13 fits into the fitting hole 9E (small diameter portion 9G) of the valve plate 9, that is, the fitting hole 9E between the tip 13A of the servo pin 13 and the valve plate 9 (small diameter portion 9G). A) even in the state immediately before the fitting where the distance (B + C) with respect to () is 0 (zero). As a result, even if the large-diameter portion 9F is provided in the fitting hole 9E, the tip 13A of the servo pin 13 and the fitting hole 9E (the small-diameter portion 9G) can be fitted first. That is, since the fitting between the servo pin 13 and the fitting hole 9E (small diameter portion 9G) of the valve plate 9 can be visually observed from the gap between the head casing 3 and the casing main body 2, the head casing 3 can be easily attached to the casing main body 2. Can be assembled.

  Further, according to the present embodiment, a tapered tapered guide portion 13C is formed at the tip 13A of the servo pin 13 on the valve plate 9 side. Thereby, the servo pin 13 can be easily fitted into the fitting hole 9E along the guide portion 13C. As a result, since the servo pin 13 itself functions as a jig for assembling the head casing 3 to the casing main body 2, there is no need to newly prepare an assembling jig such as the guide rod of the above-mentioned Patent Document 2. There is no need to make design changes such as opening a guide hole in the head casing. Therefore, the number of processing steps, the number of parts, and the cost can be suppressed, and the head casing 3 can be downsized.

  In this case, if the axial length of the servo pin is increased such that A> B or A> B + C without forming the guide portion, the rigidity of the servo pin may be reduced. In addition, the distance between the support portion that supports the servo pin in the servo piston and the load point of the servo pin on the valve plate (the point where the servo pin and the inner peripheral surface of the fitting hole of the valve plate abut) increases, so that the servo pin is actuated. The moment to be generated becomes large, and the reliability of the servo pin may be reduced.

  On the other hand, according to the present embodiment, the servo pin 13 has the guide portion 13C formed at the distal end, and the guide portion 13C is formed in a tapered shape that is tapered. It is possible to prevent the distal end 13A side (guide portion 13C) of 13 from coming into contact with the inner peripheral surface of the fitting hole 9E of the valve plate 9. Thus, the load point of the servo pin 13 on the valve plate 9 (the point of contact between the small diameter portion 9G of the fitting hole 9E and the fitting portion 13B of the servo pin 13) is shifted from the guide portion 13C to the other axial end (base end side). Therefore, it is possible to suppress an increase in the distance between the support portion of the servo pin 13 and the load point of the servo pin 13. As a result, the moment acting on the servo pin 13 can be reduced, and the reliability of the servo pin 13 can be improved.

  According to the present embodiment, the angle α between the guide portion 13C and the central axis KK of the servo pin 13 is different from the central axis LL of the valve plate 9 when the valve plate 9 is tilted to the maximum. The angle between the center axis LL of the valve plate 9 and the center axis KK of the servo pin 13 when the valve plate 9 is tilted to the minimum and larger than the angle β formed between the center axis KK of the servo pin 13 and the center axis KK of the servo pin 13. The angle γ is larger than the angle γ. Accordingly, the guide portion 13C on the distal end 13A side of the servo pin 13 has the fitting hole of the valve plate 9 regardless of whether the valve plate 9 shown in FIG. 1 is at the maximum tilt position or the minimum tilt position shown in FIG. Contact with the inner peripheral surface of 9E can be suppressed. As a result, the guide portion 13C can be prevented from interfering with the inner peripheral surface of the fitting hole 9E, so that the tilt angle of the tilt mechanism 10 can be increased even if the servo pin 13 is lengthened.

  In the above-described embodiment, the case where the valve plate 9 is set to A> B at the maximum tilt position has been described as an example. However, the present invention is not limited to this, and the valve plate may be configured such that A> B at the position of the minimum tilt, or the valve plate may be located at an intermediate position between the maximum tilt position and the minimum tilt position. May be set so that A> B. That is, the valve plate may be configured so that A> B is set at at least one of the tilt ranges between the maximum tilt position and the minimum tilt position. A> B may be set in the entire tilt range. In short, at least one of the tilting ranges, before the side surface of the concave arc-shaped sliding contact portion of the head casing and the side surface of the convex arc-shaped sliding contact portion of the valve plate are fitted, the tip of the servo pin and the valve are engaged. A> B and A> B + C may be set so that the fitting holes of the plate are fitted.

  Further, in the above-described embodiment, an example will be described in which the fitting hole 9E of the valve plate 9 is formed with a large-diameter portion 9F having an inner diameter larger than other portions of the fitting hole 9E. did. However, the present invention is not limited to this, and a configuration in which a large-diameter portion is not provided in the fitting hole may be adopted. In this case, the head casing, the valve plate, and the servo pins may satisfy the relationship of A> B.

  In the above-described embodiment, the case where the head casing 3 is assembled to the casing main body 2 by setting the valve plate 9 and the like to the maximum tilt position by gravity has been described as an example. However, the present invention is not limited to this, and a configuration in which the valve plate or the like is assembled at the minimum tilt position or a configuration in which the valve plate or the like is assembled at an intermediate position between the maximum tilt position and the minimum tilt position may be adopted. It may be. That is, the valve plate or the like may be assembled at at least one of the tilt ranges between the maximum tilt position and the minimum tilt position.

  In the above-described embodiment, the variable-capacity oblique-axis hydraulic pump 1 has been described as an example of the oblique-axis hydraulic rotary machine. However, the present invention is not limited to this, and the oblique-axis hydraulic rotating machine may be applied to a variable displacement-type oblique-axis hydraulic motor.

1 Variable displacement oblique-axis hydraulic pump (oblique-axis hydraulic rotary machine)
Reference Signs List 2 casing main body 3 head casing 3B concave arc-shaped sliding contact portion 3D side surface 3D1 edge 4 rotating shaft 6 cylinder block 6C sliding contact end surface 9 valve plate 9B convex arc-shaped sliding contact portion 9D side surface 9D1 edge 9E fitting hole 9F large diameter Part 10 Tilt mechanism 13 Servo pin 13A Tip 13C Guide part

Claims (3)

A head casing having a concave arc-shaped sliding contact portion which is provided by closing an axial opening of the casing body and is concave in an arc shape;
A convex arc shape is provided between the head casing and the cylinder block, one end surface of which is in sliding contact with the sliding contact end surface of the cylinder block, and the other end surface of which is in sliding contact with the concave arc sliding contact portion of the head casing. A valve plate serving as a sliding portion,
A tilt mechanism provided on the head casing, wherein a servo pin extending toward the valve plate from a servo piston for tilting the valve plate together with the cylinder block is connected to a fitting hole of the valve plate. The oblique shaft type hydraulic rotary machine
When the valve plate and the head casing are separated from each other in the direction of the center axis of the servo pin, and the concave arc-shaped sliding contact portion of the head casing and the convex arc-shaped sliding contact portion of the valve plate face each other at an interval. An axial distance between an edge of a side surface of the concave arc-shaped sliding contact portion of the head casing and an edge of a side surface of the convex arc-shaped sliding contact portion of the valve plate is A, and the tip of the servo pin and the valve plate When the distance in the axial direction with respect to the fitting hole is B, A> B is set in at least one position of the tilt range of the valve plate ;
At the distal end of the servo pin on the valve plate side, a spherical fitting portion is provided, and a tapered guide portion tapering to the distal end side than the fitting portion is formed.
The angle (α) between the guide portion and the center axis (KK) of the servo pin is determined by the center axis (LL) of the valve plate when the valve plate is tilted to the maximum and the center of the servo pin. The center axis (L-L) of the valve plate and the center axis (K) of the servo pin when the angle (β) between the axis (K-K) and the valve plate is minimized. -K), wherein the angle is larger than the angle (γ) with the oblique-axis hydraulic rotary machine.   2. The oblique-axis hydraulic rotary machine according to claim 1, wherein A> B is set at the maximum tilt position of the valve plate. 3.   In the fitting hole of the valve plate, a large-diameter portion having a larger inner diameter than other portions is formed on the head casing side, and when the length of the large-diameter portion in the axial direction is C, A 2. The oblique-axis hydraulic rotary machine according to claim 1, wherein the ratio is set to> B + C.

Images