JPS6098179A - Rocking plate type piston pump - Google Patents

Abstract

PURPOSE:To prevent tapping noise from generating, by forming, in a holding means, a notch fitted onto the barrel section of a shoe. CONSTITUTION:Holding members 30 slide circumferentially with respect to a rocking plate 20. Each holding member 30 is fitted through its notch 30c onto the barrel section 29a of a shoe 29 to make the shoe 29 into closely contact with a sliding surface and as well to allow the shoe 29 to radially move. The shoes 29 rotate relatively to the rocking plate 20 while they freely oxcillate with different phases with respect to the swingable plate 20, and therefore, pistons 27 are stroked. Since the notch 30c of each holding member 30 is closely fitted onto the barrel section 29a of the associated shoe 29 with no gap, the holding member 30 moves at once in association with the motion of the shoe 29, and follows indepentently from other holding members 30, thereby no tapping sound comes about.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rocking plate type piston pump, and more particularly to a shoe holding mechanism for sliding a piston against a rocking plate.

A plurality of cylinders are arranged in parallel in the circumferential direction with the drive shaft as the center and their axes parallel to the drive shaft, and these cylinders are rotated relative to a rocking plate tilted with respect to the drive shaft and fitted into each cylinder. A rocking plate type piston pump in which a piston reciprocates within a cylinder to suck in and discharge fluid is conventionally known. A rocking plate type piston pump generally requires a holding means for holding a shoe connected to the piston in sliding contact with the rocking plate. This holding means is generally constructed as follows. That is, the annular plate-shaped holding part is held on the swing plate concentrically with the swing plate and at an appropriate distance from the sliding surface thereof. A comb hole is formed at a position not corresponding to the holding member, and the shoe, which is spherically connected to the piston rond, has its body loosely fitted into the corresponding comb hole, and its flange portion is connected to the holding member and the rocking plate. is slidably held between the
As the shoe rotates relative to the swing plate, the shoe slides on the swing surface while freely moving within the hollow hole of the holding member. According to this configuration, since the piston rond is fixed to the piston, when the rocking plate is tilted, the shoe connected to the piston at or near the top dead center is displaced radially outward, The shoes that engage the piston at or near bottom dead center are deflected radially inward. In this way, as the shoe rotates relative to the rocking plate that is inclined with respect to the drive shaft, the shoe also vibrates with respect to its axis. In order to avoid blocking the swinging movement of the head, the hollow hole must have a large diameter. When the diameter of the cutout hole is increased, the diameter of the flange portion of the shoe must also be increased in order to prevent the shoe from being pulled out through the cutout hole. In this way, in the conventional structure, the size of the flange part of the shoe is not large, and as a result, the diameter of the rocking plate is also large, which necessitates an increase in the overall size of the pump. When applied to a refrigerant compressor of a nitrogen conditioner for an axle, it becomes difficult to install it in the limited storage space inside a vehicle.

In order to solve the above problem, in the proposal of the applicant of the present application in the earlier Japanese Patent Application No. 131336/1983, as shown in FIGS.
and a second holding member 2. First holding part'@1
The ring has a center hole 1a into which the drive shaft 3 is loosely fitted, and a plurality of hollow holes 1b which are formed in parallel in the circumferential direction near the outer periphery and have a diameter much larger than that of the body 4a of the shoe 4. formed into a shape. The second holding member 2 is #! an axial cylindrical portion 2a that loosely passes through the center hole 1a of the holding member 1 of the first holding member 1 and is removably fitted into the center hole 5a of the rocking plate 5; The holding part 1 is made up of a radial flange part 2b that is larger than the center hole 1a of the holding part 1 and has an outer diameter that does not interfere with the movement of the shoe 4. The first holding member 1 loosely fits the body portion 4a of the corresponding shoe 4 into the slotted hole 1b, and is held by the flange portion 2b of the second holding member 2 to hold the flange portion 4b of the shoe 4. Sliding surface 5 of rocking plate 5
b, so that the first holding member l is slidably and closely contacted with the shoe 4, so that the first holding member 1 moves parallel to the sliding surface 5b of the rocking plate 5 as the shoe 4 moves. In this way, the first holding member 1 is not held concentrically with the rocking plate 5, but is arranged so as to freely move following the movement of the shoe 4.
B can be cut and pulled by l'', and the drawbacks of the conventional holding means can be solved.

By the way, according to this tapered configuration, since the shoes 4 located at different circumferential positions of the rocking plate 5 are deflected by slightly different amounts of deviation with respect to the rocking plate 5, the first holding member The diameter of the hollow hole 1b of the shoe 4 is set to be slightly larger than that of the body 4a of the shoe 4 to allow the shoe 4 to be displaced. However, as the shoes 4 in different phases of each piston reciprocate, they sequentially deviate in their own radial direction, and when the first holding member 1 moves to follow the shoes 4, the body of the shoe 4 There is a problem in that the portion 4a collides with the periphery of the hollowed-out hole 1b, which has a slightly larger diameter, and generates a hammering sound.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to prevent the occurrence of the above-mentioned hammering noise, and to reduce the size of the retaining portion and the shoe, thereby making it possible to downsize the piston pump as a whole. The object of the present invention is to provide a rocking plate type piston pump.

In order to achieve the above object, the present invention provides a drive shaft, a cylinder of &a which is aligned circumferentially with the drive shaft as the center and the drive shaft and the axis at ΔF A piston rond fixed to the piston, a disk-like rocking plate that is tilted with respect to the drive shaft and can rotate relative to the piston rond as the drive shaft rotates, corresponds to Body a freely connected to piston rond
In a rocking plate type piston pump, the rocking plate type piston pump includes a shoe having a flange portion that slides in contact with a sliding surface of the rocking plate, and a holding means for holding the shoe in sliding contact with the rocking plate, the holding means holding the shoe in sliding contact with the rocking plate. , each has a notch extending in the radial direction of the rocking plate that fits into the body of the corresponding shoe, and has a notch extending in the radial direction of the rocking plate that fits into the body of the corresponding shoe. A gap corresponding to the thickness is formed, and a plurality of holding parts are formed to interpose and hold the flange portion, and the holding member is engaged with the swinging plate by allowing the holding member to slide in the circumferential direction relative to the swinging plate. It consists of a means of securing

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. The piston pump body 1o has a cylindrical case ll
a and the cylinder head llb are joined to form the housing 1.
1, and a cylinder block 12 is integrally formed inside a cylindrical case 11ai;ii. The cylinder block 12 has a drive shaft 13 as a center and a drive shaft 13 as a center.
A plurality of cylinders 14 are formed in parallel in the circumferential direction with their axes parallel to each other. The drive shaft 13 is located approximately on the central axis of the housing 11, and one end is supported by a ball bearing 15 in the center hole 12a of the cylinder block 12, and the other end is supported at the front of the case lla (right side in FIG. 2). A pulley 17 is fitted to the shaft end of the shaft, and a sleeve-shaped slider 18 that slides back and forth on the shaft is fitted to the phase drive shaft 13. A vertical trunnion bin 19 is installed on the drive shaft 13. A disk-shaped swinging plate 20id has its center hole 20a loosely fitted onto the slider 18, and the trunnion bin 19 is fitted into a hole (not shown) drilled in the inner peripheral surface of the center hole 2Qa. The swing plate 2o and the slider 18 are engaged, so that the center of the swing plate 2o moves together with the slider 18 on the drive shaft 13, and moves in the drive shaft direction with respect to the drive shaft 13 around the trunnion bin 19. Can be tilted.

The swing plate 20 also includes a pivot 21 located on the side opposite to the cylinder block and located near a point on the extension line of the axis of the constant piston 27' in the cylinder 14.
is attached via a bracket 22. The pivot 21 has a guide hole 24 provided in an arm member 23 whose boss portion 23a is coupled to the drive shaft 13 and rotates integrally therewith.
The rotation is transmitted to the swing plate 2o of the drive shaft 13, and the swing plate 20 is tilted using the trunnion bin 19 as a movement fulcrum and the pivot 21 as a tilt fulcrum.

The arm side 23 is supported by a large ball bearing 25 mounted on the case lla, and the front part of the drive shaft 13 is substantially supported by the case lla by the hole bear link 25 via the upper arm side 23. It has become. A shaft seal device 16 is fitted on the outer periphery of the boss portion 23a on the arm side 23.

One end of the slider 18 is slidably fitted into the blind center hole 12a of the cylinder block 12, and
An oil chamber 26 is defined by the inner wall and the end face of the slider 18, and hydraulic oil is caused to flow into and out of the core oil chamber 26 from a hydraulic mooring edge (not shown) to move the slider 18 on the drive shaft 13.

On the other hand, long cylindrical pistons 27 are inserted into a plurality of concentric cylinders 14 formed in the cylinder block 12 so as to reciprocate automatically, and extend on the central axis of the pistons 27 and toward the rocking plate 20 side. A piston rod 28 is integrally fixed, and a sphere 28a is formed at the tip thereof. A hole 29C of a shoe 29 formed by a body portion 29a and a flange portion 29b is swingably connected to this sphere 28a. The basic configuration described above is the same as that of the rocking plate type piston pump of the earlier application. Here, the holding means for slidingly contacting and following the sliding surface 20b of the rotating and swinging rocking plate 20 with the shoe 29 is constructed as follows in the present invention. That is, a plurality of (5) holding members 30 each hold each of the shoes 29 (5 in this example) corresponding to the piston 27.
is set up. Each holding member 30 is formed of a substantially rectangular plate-like body with an m6L-shaped cross section, and a groove 30a' having a U-shaped cross section is formed on the inner surface of one end forming each axial outer peripheral portion 30a.
It is slidably engaged with a radial annular flange 20C formed on the outer periphery of the rocking plate 20. and each holding part month 3
0 is arranged such that the long axis of the substantially rectangular radial portion 30b is directed toward the center of the rocking plate 20, and the inner surface of the radial portion 30b is parallel to the rocking surface 20b of the rocking plate 20. ing. Furthermore, a gap corresponding to the thickness t of the flange portion 29b of the shoe 29 is formed between the inner surface of the radial portion 30b and the sliding surface 20b of the swing plate 20 in the axial outer peripheral portion 3Qaf of each holding member 30. The length dimension is set so that A swing plate 20 is provided on the radially inner end surface of the radial portion 30b.
A longitudinal notch 30C opening toward the center of the radial direction is formed, and the width of the notch 30c is 29.
The body portion 29a is set substantially equal to the body portion 29a of
a is tightly and slidably fitted into the notch 30c. Also, the length of the notch 30C is such that the shoe 29 is radially outward and inner 111 of the rocking plate 20! + over the required maximum stroke!
, is set to a length that allows movement of about one piece and prevents it from coming off.

Further, an arcuate groove 30d into which a ring member 31 for engaging and holding each holding member 30 on the swing plate 20 is slidably fitted is formed on the outer surface of the outer peripheral portion 30a of each holding member 3o.

Each of the holding members 30 has a groove 3 on the inner surface of its outer peripheral portion 30a.
0a' is engaged with the annular flange 20C on the outer periphery of the rocking plate 20, and the ring member 31 is similarly fitted into the arcuate groove 30d on the outer periphery 30a, and the inner surface of the radial portion 30b and the sliding surface 20b are The flange portion 29b of the shoe 29 is interposed and held in between, and each shoe 29 is slidably fitted to the rocking plate 20 in the circumferential direction, so each shoe 29 can rotate relative to the rocking plate 20 and move outward in the radial direction. At the same time, it can also be freely displaced in the circumferential direction together with the holding member 30.

The operation of the rocking plate type piston machine of the present invention constructed as described above will now be described. The belt is moved to valve 1 by power from an external drive source (not shown). The pulley 17 is rotated, and the rotation is transmitted to the drive shaft 13. At this time, if the hydraulic control mechanism constituted by the oil chamber 26 etc. is not activated, the slider 1
8 is biased under pressure in FIG. 3 due to the action of a spring (not shown), and the rocking plate 20 is in a vertical neutral position with the pin 21 as a fulcrum. In this neutral position, all the pistons 27 are set to be located at the top dead center position of the cylinder 14. In the neutral position, the rotating swing plate 20 does not swing, so the piston 27 does not stroke, and therefore no fluid is sucked or discharged.

Next, when the control mechanism is activated and the slider 18 is moved to the right in the figure, the rocking plate 20 tilts about the pivot 21, and the bottom dead center position of the piston 27 is moved to the right in the figure. The stroke length of the piston increases as the piston moves, and when the rocking plate 20 takes the maximum angle of inclination, the piston 27 reaches its maximum stroke.#) The maximum discharge amount is obtained.

As described above, since the piston 27 is located at the top dead center position when the swing plate 20 is in the neutral position, when the inclination angle of the swing plate 20 is small, the piston 27 is at its top dead center position, that is, at the top dead center position of the cylinder. Since the suction stroke is started from the position where the capacity of the space to be compressed is the maximum /JS, the compression efficiency of the compressed fluid does not decrease even if the discharge amount is affected.

In this way, by changing the inclination angle of the rocking plate 20, the discharge amount can be controlled steplessly from zero to the maximum.
An intermittent clutch such as a constant displacement piston pump is not required in connection with the engine. During the above operation, the holding member 30 is used as a holding means for causing the shoe 29, which is freely connected to the end of the piston rond 28, to slide and follow the rocking plate 20 that swings and rotates, thereby giving a stroke to the piston 27. That is, each holding member 30 itself slides in the circumferential direction with respect to the rocking plate 20, and the holding portion 30 is fitted into the body 29a of the shoe 29 through its notch 30C, and the shoe 29f slides. Since each shoe 29 is brought into close contact with the surface 20b and allowed to move in the radial direction, each shoe 29
While freely oscillating in different phases, the piston 27 rotates relative to the rocking plate 20 to give a stroke to the piston 27. At this time, the notch 30C of the holding member 30 and the shoe 2
Since the holding member 3o is closely fitted with the body portion 29a of the shoe 29 without any play, the holding member 3o moves immediately with the movement of each shoe 29 and follows independently from the other holding members 30, so there is no hitting sound. Does not occur.

FIG. 5 shows another embodiment of the holding part, in which components corresponding to those of the previous embodiment are designated by the same reference numerals. This holding member 30' is composed of a substantially rectangular plate-shaped body having an abbreviated cross section, similar to the holding member 30 of the previous embodiment, and has an inwardly bent portion 30' at one end 30'a of its axial outer periphery. a' is formed, and the core portion 30/a/ is slidably engaged with the surface of the outer peripheral portion of the rocking plate 20 on the side opposite to the holding member. In other configurations, that is, when the bent portion 3 ()/a/ is secured to the outer peripheral portion of the rocking plate 20, the inner surface 30'b' of the radial portion 30'b is the sliding surface of the rocking plate 20. 20b and extends parallel to the inner surface 30'
A gap corresponding to the floating type t of the flange portion 29b of the shoe 29 is formed between b' and the sliding surface, and a radial portion 30'
In b, there is a notch 30 facing the center of the rocking plate 20 (ill).
The configuration in which 'C' is formed is the same as that of the holding member 30 of the previous embodiment. In order to slidably hold this holding member 30' on the outer periphery of the rocking plate 20, an annular frame side 317 formed by bending the periphery in the axial direction is fitted onto the outer periphery of the holding member 3σ,
The frame member 31' is fixed to the non-sliding surface side of the swing plate 20 with a plurality of bolts 32. This holding part 4130'
The functions and effects of the holding member 30 are the same as those of the holding member 30 of the previous embodiment, so the explanation thereof will be omitted.

As explained above, according to the present invention, in a rocking plate type piston pump, a holding means for holding the shoe in sliding contact with the rocking plate is provided on each of the shoes and is fitted into the body of the corresponding shoe. It has a notch extending in the radial direction of the rocking plate, and forms a gap corresponding to the thickness of the flange portion of the shoe between the sliding surface of the rocking plate and holds the flange portion therebetween. Because the holding member on the side of the ship is configured with a retaining means that enables sliding in the circumferential direction relative to the sliding plate and engages with the rocking plate, the holding member is no longer in the form of a conventional single plate. Comparatively, the pump itself can be made smaller and lighter.For example, when the pump according to the present invention is applied to a refrigerant compressor for a vehicle air conditioner, it can be easily installed in a limited storage space in a vehicle. In addition to being easy to install, the shoe and the holding member are engaged with each other through the notch without any play, so that no hitting noise is generated and quiet operation is possible.

Furthermore, since each holding member is divided into multiple pieces and is lightweight,
The inertial force of the holding member acting on the shoe is reduced, increasing the durability of the shoe and the rond.

In the above embodiment, a variable displacement type rocking plate type piston pump was described in which the rocking plate was rotated by the drive shaft with respect to the stationary cylinder, and the displacement was variable, but when the rocking plate was stationary and the cylinder was rotated by the drive shaft ) The present invention is also applicable to rotating type piston pumps and fixed displacement piston pumps in which the inclination angle of the rocking plate is fixed.

[Brief explanation of drawings]

Fig. 1 is a sectional view of main parts of a piston pump proposed earlier by the applicant, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, and Figs. Embodiments of the invention are shown, and the third
The figure is a joint sectional view of the first embodiment, and FIG. 4 is the IV-
Cross-sectional view of the main part along line IV, 8r! Fig. 5 is a detailed view of the handling parts of the second embodiment. 10... Rocking plate type piston pump, 13... Drive shaft, 14... Cylinder, 20... Rocking Board, 20b...
・Sliding surface, 27... Piston, 28... Piston rod, 29... Shoe, 29a... Body, 29b...
・Flange part, 30.30'... Holding member, 30C,
30'C...Notch. Patent attorney Toshihiko Watanabe, representative of applicant Diesel Kiki Co., Ltd.

Claims (1)

[Claims] 1. A drive shaft, a plurality of cylinders arranged circumferentially around the drive shaft with their axes parallel to the drive shaft, a piston fitted into each cylinder so as to be able to reciprocate, and a cylinder fixed to the piston. a piston rond, a disc-shaped oscillating plate that is inclined with respect to the drive shaft and can rotate relative to the piston rond as the drive shaft rotates, and a body freely connected to the corresponding piston rond and a sliding plate between the oscillating plate and the piston rond. In a rocking plate type piston pump comprising a shoe formed with seven rank portions that slide on a moving surface, and a holding means for holding the shoe in sliding contact with a rocking plate, the holding means is provided on each of the shoes, Each has a notch extending in the radial direction of the rocking plate that fits into the body of the corresponding shoe, and a gap corresponding to the thickness of the flange of the shoe between the rocking plate and the sliding surface of the rocking plate. a oscillating plate type piston pump comprising: a retaining means for engaging the oscillating plate while allowing the holding member to slide in the circumferential direction relative to the oscillating plate;