JPH0648177Y2 - Lubricating swing arm device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a swing arm device, and more particularly to lubrication of a sliding surface of a pivot shaft of a swing arm.

2. Description of the Related Art In a rocking arm device, a rocking arm rotatably supported by a supporting member via a pivot shaft rocks within a certain angle range, and is used for driving a vacuum pump, for example. One end of the swing arm is engaged with the piston of the vacuum pump and the other end is engaged with the cam, and the piston is reciprocated by the swing of the swing arm as the cam rotates. In this swing arm device, the pivot shaft is often rotatable with respect to either one of the swing arm and the support member, but may be rotatable with respect to both. In the former case, the pivot shaft is fixed to the support member and the swing arm is rotatable about the pivot shaft, and in the former case, the pivot shaft is rotatably supported by the support member and the swing arm is attached to the pivot arm. There is a case where they are fixed to the shaft and both swing together.

In either case, the sliding surface, that is, the contact portion between the outer peripheral surface of the pivot shaft and the inner peripheral surface of the swing arm and / or the shaft hole of the support member is usually lubricated. The applicant previously proposed in the application of Japanese Utility Model Application No. 61-104529 to supply the lubricating oil to the above-mentioned clearance from the outside of the swing arm. In this swing arm device, the swing arm is provided rotatably around a pivot shaft supported by a supporting member, and a roller is rotatably attached to one end of the swing arm, and a cam is provided on an outer peripheral surface thereof. Of the rocking arm, the rocking arm rocks around the pivot shaft by following the cam surface while rotating. The contact portion between the roller and the cam is lubricated by the lubricating oil injected from below, and this lubricating oil is used for lubricating the sliding surface between the swing arm and the pivot shaft. Specifically, the swing arm is provided with an oil guide hole, one end of which opens on the upper surface of the swing arm and the other end of which opens on the outer peripheral surface of the pivot shaft, and jets toward the contact portion between the roller and the cam. After the lubricated oil is wound up, it falls and enters the oil guide hole to lubricate the sliding surface between the pivot shaft and the swing arm.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in this swing arm device, since one oil guide hole is provided on one side of the vertical plane including the center line of rotation of the swing arm, the lubricating oil that is generated by the swing motion is prevented. There was a problem that lubricating oil became insufficient due to scattering. When the swing arm is rotated, the moving directions of the parts on both sides of the vertical plane are opposite to each other. When the part on one side descends, the part on the other side rises, and when ascending, the lubricating oil in the oil guide hole moves to the outer peripheral surface side of the pivot shaft due to inertia and is effectively provided for lubrication. However, when descending, the lubricating oil in the oil guide hole is left behind at the original position and scattered, and there is a risk of running out of lubricating oil and causing abnormal wear or seizure.

Means for Solving the Problems In order to solve the above problems, the present invention provides a swing arm, a first end of which is opened on an upper surface of the swing arm and a second end of which is an outer peripheral surface of the pivot shaft. A plurality of oil guide holes that open in a gap between the swing arm and / or the inner peripheral surface of the shaft hole of the support member are formed, and first ends of the plurality of oil guide holes are formed.
At least one opening is provided on each side of a vertical plane including the center line of rotation of the swing arm.

When the pivot shaft is fixed to the support member and the swing arm is rotatable about the pivot shaft, the second end of the oil guide hole is located on the outer peripheral surface of the pivot shaft and in the shaft hole of the swing arm. When the pivot shaft is rotatably supported by the supporting member and the swing arm is fixed to the pivot shaft and both swing together, it is provided so as to open in the gap with the peripheral surface. The second end is provided so as to pass through the inside of the pivot shaft and open in a gap between the outer peripheral surface of the pivot shaft and the inner peripheral surface of the shaft hole of the support member. When the pivot shaft is rotatable with respect to both the swing arm and the support member, it is desirable to employ both of the above means.

Action and Effect In the swing arm device configured as described above, the first ends of the plurality of oil guide holes are opened on both sides of the vertical plane that serves as a boundary in the moving direction of the swing arm. When the swing arm rotates, even if the lubricating oil in the oil guide hole that opens on one side scatters, the lubricating oil in the oil guide hole that opens on the other side will be effectively used for lubrication. , The lubricating oil is always supplied to the gap between the outer peripheral surface of the pivot shaft and the inner peripheral surface of the swing arm and / or the shaft hole of the support member, eliminating the lack of lubricating oil and avoiding abnormal wear and seizure. To be done.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a view showing a piston type vacuum pump provided with a swing arm device according to an embodiment of the present invention, and 10 in the drawing is a housing. The housing 10 includes a container-shaped housing body 12 and a lid body 14 that closes an opening of the housing body 12, and a piston 18 is slidably fitted in the housing body 12 via a lining 16. . An annular O-ring groove 20 that opens to the inner peripheral surface of the housing body 12 is formed on the outer peripheral portion of the piston 18,
The O-ring 22 is fitted in the O-ring groove 20 to maintain airtightness, and the pump chamber is provided between the piston 18 and the lid 14.
26 are formed.

The piston 18 is biased by the taper coil spring 30 in a direction to reduce the volume of the pump chamber 26. A rod 32 is attached to the piston 18 in a direction in which it extends toward the opposite side of the pump chamber 26. The rod 32 has one end penetrating the piston 18 and projected toward the pump chamber 26 side, and is fixed to the piston 18 by a nut 34 screwed to the protruding end, while the other end. Department is
It is slidably fitted in a support hole 36 formed in the housing body 12.

Further, an L-shaped joint portion 40 forming an intake passage communicating with the pump chamber 26 is formed on the upper surface of the lid 14 of the housing 10, while the pump chamber 26 and the engine cam are provided on the side wall of the housing body 12. An L-shaped discharge passage 42 that communicates with the chamber is formed, and a suction valve (not shown) and a discharge valve 44 are provided at the ends of the suction passage and the discharge passage 42 on the side that communicate with the pump chamber 26, respectively. It is provided. The discharge valve 44 is
A casing 52 in which a valve 46, a spring 48, and a valve seat 50 are assembled is assembled in the discharge passage 42, and only discharge of air from the pump chamber 26 is allowed. Intake valve and discharge valve
It has the same structure as 44 and allows only the inflow of air from the suction passage into the pump chamber 26.

Further, a flange portion 54 that extends outward in the radial direction is provided at a portion of the rod 32 that is supported by the support hole 36, and a portion of the rod 32 that is closer to the piston 18 than the flange portion 54. Rocker arm 56 as a swing arm
Has one end engaged. This rocker arm 56
Is rotatably attached to a pivot shaft 58 whose both ends are supported by the housing body 12, and is engaged with the rod 32 at a yoke portion 60 formed at one end thereof. That is, in the present embodiment, the support portions 61 that support both ends of the pivot shaft 58 of the housing body 12 form a support member. The other end of the rocker arm 56 is formed so as to extend obliquely upward, and its tip end is formed into a yoke shape to support both ends of the support shaft 62.
An inner roller 64 is rotatably fitted to the support shaft 62, and an outer roller 66 is rotatably fitted to the outer side of the inner roller 64. The rocker arm 56 is rotated by the engine at the outer roller 66. It is brought into contact with the outer peripheral surface of the driven cam 68, that is, the cam surface 70. The cam 68 is an eccentric cam mounted eccentrically with respect to the axis of the cam shaft 72, and when the cam 68 is rotated, the outer roller 66
By following the cam surface 70 while rotating, the rocker arm 56 is swung about the pivot shaft 58 within a certain angle range, and the piston 18 is moved forward and backward to suck and exhaust air. The rotation direction of the outer roller 66 is determined so that any one point on the outer peripheral surface of the outer roller 66 approaches the upper surface of the rocker arm 56 from above as the outer roller 66 rotates. ing.

As shown in FIG. 3, the support shaft 62 is formed with an axial hole 74 that axially penetrates the central portion thereof. The inner peripheral surfaces of the openings at both ends of the axial hole 74 are tapered surfaces having a larger diameter toward the opening side, respectively, and are supported from the axial hole 74 at the axially intermediate portion of the peripheral wall of the support shaft 62. A pair of radial holes 76 extending to the outer peripheral surface of the shaft 62 and facing the inner peripheral surface of the inner roller 64 are formed. On the inner peripheral surface of the axial hole 74, an annular protrusion 78 extending toward the center is further formed at a position near one opening.

The cam shaft 72 is rotatably supported by being sandwiched between a cylinder head 82 and a cover 84 of the engine via a bush 80. An oil passage 86 for supplying lubricating oil is formed on the outer peripheral surface of the bush 80 in the cylinder head 82, and the cylinder head is branched from the oil passage 86.
A nozzle 88 that opens at the end face of the side of 82 that faces the vacuum pump is formed. In this nozzle 88, the lubricating oil jet ejected from the nozzle 88 causes the rocker arm 56 to reach the bottom dead center,
That is, when the outer roller 66 is in a position where it comes into contact with the surface of the cam surface 70 that is closest to the axis of the cam shaft 72, the outer roller 66 hits the open end of the axial hole 74 formed in the support shaft 62 and the rocker arm 56 moves upward. It is formed in a direction in which the outer roller 66 contacts the contact portion between the outer roller 66 and the cam 68 when the outer roller 66 moves to a position where the outer roller 66 contacts the surface of the cam surface 70 farthest from the axis of the cam shaft 72. In this embodiment, the nozzle 88
Constitutes the supply means for supplying the lubricating oil.

The rocker arm 56 is formed with two oil guide holes 92, 94 having a first end opening on the upper surface of the rocker arm 56 and a second end opening facing the outer peripheral surface of the pivot shaft 58. These oil guide holes 92 and 94 are vertical planes including the rotation center line of the rocker arm 56 (hereinafter, this plane is referred to as a boundary plane).
Are formed on both sides of the rocker arm 56, and the end of the rocker arm 56 on the upper surface is funnel-shaped. Further, an extremely shallow annular groove 98 is formed in the portion of the pivot shaft 58 where the oil guide holes 92, 94 are opened, as exaggeratedly shown in FIG.

In the vacuum pump configured as described above,
During operation, the lubricating oil jet is jetted from the nozzle 88 in the direction shown by the alternate long and short dash line in FIGS.
4, can be hung on the outer roller 66, the cam 68, The lubricating oil jet is designed to support shaft 62 when rocker arm 56 is at bottom dead center.
On the opening end of the axial hole 74 formed in
Flows in. Since the opening end of the axial hole 74 is a tapered surface, the lubricating oil easily flows into the axial hole 74, and the inflowing lubricating oil enters between the support shaft 62 and the inner roller 64 from the radial hole 76. The outer peripheral surface of the support shaft 62 and the inner peripheral surface of the inner roller 64 are lubricated. At this time, the protrusion formed in the axial hole 74
Since 78 blocks the flow of the lubricating oil, the lubricating oil is encouraged to flow into the radial holes 76, and the support shaft 62 and the inner roller 64 are well lubricated.

If the rocker arm 56 is at top dead center,
Lubricating oil jet injected from 88
It is applied to the contact portion with 68, lubricates both contact surfaces, and is wound up by the rotation of the outer roller 66 and sent above the rocker arm 56. By jetting the lubricating oil jet,
The engine room is filled with oil mist, a part of which drops onto the upper surface of the rocker arm 56, passes through the upper surface and flows into the oil guide hole 94, and another part falls into the direct oil guide hole. Enter 92,94 and rocker arm 56 and pivot 58
Lubricate the sliding surface with. When the rocker arm 56 rotates from the bottom dead center to the top dead center, the oil guide hole 92 descends and the oil guide hole 94 rises, while if the rotating direction is reversed, the oil guide hole is formed.
92 rises and oil guide hole 94 descends. Then, when the oil guide hole descends, the lubricating oil in the oil guide hole is left behind due to inertia and jumps out from the oil guide hole, whereas when it rises, the lubricating oil in the oil guide hole is inertial. As a result, it is positively moved to the annular groove 98 side and provided for lubrication. Since the oil guide holes 92 and 94 are provided on both sides of the boundary plane which is a division in the moving direction of the rocker arm 56, when the rocker arm 56 swings, the lubricating oil in either one of the oil guide holes is positively activated. Since it is supplied to the sliding surface, the lubricating oil will not run short and abnormal wear and seizure will not occur.

Further, since the annular groove 98 is formed at the portion where the second ends of the oil guide holes 92, 94 of the pivot shaft 58 are opened, the oil guide holes are formed.
The lubricating oil flowing from 92, 94 into the gap between the rocker arm 56 and the pivot shaft 58 spreads in the circumferential direction through the annular groove 98,
Both are lubricated without a gap.

Further, the lubricating oil in one of the oil guide holes 92, 94 scatters as the rocker arm 56 swings, which lubricates the sliding surface between the rocker arm 56 and the pivot shaft 58. The lubricant oil that has become high temperature is discharged and the high temperature lubricant oil and the low temperature lubricant oil supplied from outside are exchanged, so the temperature rise of the lubricant oil is small and seizure is even better. To be avoided.

In addition, on the upper surface of the rocker arm 56, one end is close to the outer peripheral surface of the outer roller 66, and the other end is formed with an oil guide passage that connects to the oil guide hole 94. 94
You may be positively guided to.

Further, the rocker arm 56 is provided with an oil discharge hole, one end of which opens to the annular groove 98 and the other end of which opens to the lower surface of the rocker arm 56,
The lubricating oil may be discharged.

Another embodiment of the present invention is shown in FIG. In this embodiment, the pivot shaft 110 is rotatably supported by the housing body 12, the rocker arm 112 is fixed to the pivot shaft 110 and rocks integrally, and the second ends of the two oil guide holes 114 and 116 are the same. It was opened at a point. That is, in this embodiment, the portion of the housing body 12 that rotatably supports the pivot shaft 110 constitutes the support member.

The pivot shaft 110 extends in the axial direction at the center of the pivot shaft 110.
Is formed with an axial hole 118 reaching a portion supported by the housing body 12, and the oil guide holes 114 and 116 have first ends opened on both sides of the boundary plane on the upper surface of the rocker arm, respectively, and second ends. The sides are joined together in the axial hole 118, and are opened in the gap between the pivot shaft 110 and the shaft hole of the housing body 12 at the tips of the pair of branch passages 120. The tip of the branch passage 120 is the oil guide hole 114.
It is the second end of.

The lubricating oil flowing into the oil guide holes 114, 116 is supplied to the gap between the pivot shaft 112 and the housing body 12 via the axial hole 118 and the branch passage 120. In this embodiment, as in the case of the above-described embodiment, the lubricating oil in either one of the oil guide holes is always positively supplied to the above-mentioned gap, the lubricating oil does not run short, and the lubricating oil slides. There is an advantage that the surface is evenly distributed.
Lubricating oil passes through the axial hole 118, and is made to flow into the gap between the pivot shaft 58 and the housing body 12 at two diametrically separated places by the branch passages 120 provided in opposite directions. As a result, the lubricating oil is evenly supplied to the sliding surface.

In the above embodiment, one oil guide hole is provided on each side of the boundary plane, but a plurality of oil guide holes may be provided on one side or both sides.

Furthermore, in the above-described embodiment, the rocker arm 56 has a posture in which it extends obliquely upward from the pivot shaft 58, but it may extend in other directions such as the horizontal direction. Even in such a case, the lubricating oil that has dropped onto the upper surface of the rocker arm can flow into the oil guide hole along the rocker arm due to the change in the posture caused by the rocker arm swinging.

The supply means for supplying the lubricating oil is rollers 64, 66, cams.
Not limited to a nozzle that injects a lubricating oil jet from below to 68, etc., it may be configured to drip the lubricating oil from above the outer roller 66 and the cam 68 to their contact parts, and the rollers 64, 66, A means for supplying the lubricating oil to the pivot shaft 58 and the rocker arm 56 may be provided separately from the means for supplying the lubricating oil to the cam 68.

In addition, although not exemplified, various modifications and improvements are made based on the knowledge of those skilled in the art such that the present invention can be applied to a swing arm device provided in a device other than a vacuum pump. The present invention can be implemented in this manner.

[Brief description of drawings]

FIG. 1 is a front sectional view showing a vacuum pump equipped with a swing arm device according to an embodiment of the present invention. FIG. 2 is a perspective view showing the pivot shaft supporting the rocker arm in the vacuum pump. FIG. 3 is a front sectional view showing, together with a cam shaft, a roller attached to the rocker arm and a cam with which the roller is brought into contact. FIG. 4 is a front sectional view showing an essential part of a swing arm device which is another embodiment of the present invention. 12: Housing body, 56: Rocker arm 58: Pivot shaft, 82: Cylinder head 88: Nozzle, 92,94: Oil guide hole 110: Pivot shaft, 112: Rocker arm 114, 116: Oil guide hole

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takeshi Nakakobara, 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Creator Hirohisa Ito 1-1, 1-Kyowa Town, Obu City, Aichi Prefecture Within Kogyo Co., Ltd. (56) Bibliographic references Sho 57-144620 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A swing arm device in which a swing arm, which is rotatably supported by a support member via a pivot shaft, swings within a certain angle range, wherein the swing arm has a first end that swings. A plurality of oil guide holes which are opened in the upper surface of the pivot shaft and whose second end is opened in the gap between the outer peripheral surface of the pivot shaft and the inner peripheral surface of the swing arm and / or the shaft hole of the supporting member. A lubrication type swing arm device characterized in that at least one first end of each of the plurality of oil guide holes is opened on each side of a vertical plane including a rotation center line of the swing arm.