JPH0444912Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a swinging arm device in which a swinging arm equipped with a roller as a cam follower is rotated by a cam. This relates to the lubrication of the sliding surfaces between the pivot shaft that supports the movable arm and the swing arm.

Conventional technology This type of swinging arm device is
This is already known from publications such as No. This swing arm device opens and closes the intake valve or exhaust valve of a cylinder in an overhead cam type engine. In this system, a swinging arm is rotatably provided around a pivot shaft supported by a housing as a support member, and a roller is rotatably attached to one end of the swinging arm.
By contacting the cam surface of the cam on its outer peripheral surface and following the cam surface while rotating, the swing arm swings around the pivot shaft to open and close the valve.

In this way, in the swinging arm device, the other end of the swinging arm is engaged with the operating member, and the operating member performs a predetermined operation by swinging the swinging arm. The contact area between the roller and the cam and the sliding surface between the pivot shaft and the swing arm are prone to wear. In particular, the pivot shaft is subject to loads from the cam and the actuating member on both ends of the swing arm, which increases the surface pressure on the sliding surface and easily causes wear. Therefore, the swing arm device described in the above publication In this system, lubricating oil is supplied to each contact portion between the roller and the cam, and between the pivot shaft and the swinging arm to reduce wear and prevent seizure and shortened life.

An oil passage extending in the axial direction is provided in the pivot shaft that rotatably supports the swing arm, and is connected to a lubricating oil supply source. The moving arm has
An oil passage is provided, one end of which opens into the shaft hole into which the pivot shaft is fitted, and the other end of which opens toward the roller. The lubricating oil supplied to the oil passage in the pivot shaft enters the sliding surfaces of the pivot shaft and swing arm through the oil hole to lubricate them. When the oil passage of the swing arm and the oil passage of the swing arm coincide, lubricating oil is injected from the oil passage toward the roller, and the contact portion between the cam and the roller is lubricated.

Problems to be Solved by the Invention However, if the oil passage is provided within the movable member, manufacturing of the movable member becomes troublesome and increases the cost. Further, although it is essential to connect the oil passage in the pivot shaft that supports the swing arm to a lubricating oil supply source, this connection may be difficult depending on the surrounding circumstances.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a swinging arm device of the type described above, in which the direction of rotation of the roller is determined by an arbitrary point on the outer peripheral surface of the roller. The direction is determined so that the upper surface of the swing arm is approached from above as the roller rotates, and the outer circumferential surface of the roller contacts the cam surface at at least one position when the roller follows the cam surface. Provide a supply means for supplying lubricating oil to the
The swinging arm has one end opening on the top surface of the swinging arm, the other end opening in the gap between the outer circumferential surface of the pivot shaft and the inner circumferential surface of the shaft hole of the swinging arm, and the other end opening on the top surface of the swinging arm. It is characterized by forming an oil guide hole whose side opening end is wider than the other part.

In the swing arm device configured as described above, the lubricating oil supplied to the contact portion between the outer circumferential surface of the roller and the cam surface lubricates the contact portion, and
As the roller rotates, the lubricating oil is rolled up above the swinging arm and falls onto the top surface of the swinging arm.The lubricating oil flows along the top surface of the swinging arm and flows through the oil guide hole between the pivot shaft and the swinging arm. Lubricate both sliding surfaces. The opening end of the oil guide hole on the top surface of the swing arm is wider than the other parts, so the lubricating oil flowing along the top surface of the swing arm easily flows into the oil guide hole.
Furthermore, the lubricating oil present in the form of mist near the swing arm is widely collected, resulting in better lubrication.

Effects of the Invention As described above, in the lubricated swing arm device according to the present invention, lubricating oil is supplied from outside the swing arm, and there is no need to provide an oil passage inside the swing arm. The swing arm is easy to manufacture and costs can be reduced. Further, providing a lubricating oil supply means outside the swing arm has a higher degree of freedom and can be performed easily compared to the case where the oil passage in the pivot shaft and the lubricating oil supply source are connected.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 is a diagram showing a piston-type vacuum pump equipped with a swing arm device, which is an embodiment of the present invention, and in the figure, 10 is a housing. The housing 10 includes a container-shaped housing body 12;
A lid body 1 that closes the opening of the housing body 12
4, and a piston 18 is slidably fitted into the housing body 12 via a lining 16. An annular O-ring groove 20 that opens to the inner circumferential surface of the housing body 12 is formed on the outer circumference of the piston 18.
An O-ring 22 is fitted to maintain airtightness, and a pump chamber 26 is formed between the piston 18 and the lid 14.

The piston 18 is a tapered coil spring 30
is biased in a direction to decrease the volume of the pump chamber 26. The piston 18 also has a rod 32 extending in the direction opposite to the pump chamber 26.
is installed. The rod 32 has one end extending through the piston 18 and protruding toward the pump chamber 26, and is fixed by screwing a nut 34 onto the protruding end, while the other end is Support hole 3 formed in housing body 12
6 and is slidably fitted and supported.

Further, an L-shaped joint 40 that forms a suction passage communicating with the pump chamber 26 is formed on the top surface of the lid 14 of the housing 10, while a side wall of the housing body 12 is formed with a cam between the pump chamber 26 and the engine. An L-shaped discharge passage 42 communicating with the pump chamber 26 is formed at the end of each of the suction passage and discharge passage 42 on the side communicating with the pump chamber 26.
A discharge valve 44 and a suction valve (not shown) are provided. The discharge valve 44 includes a valve element 46 and a spring 4.
8 and the casing 5 assembled with the valve seat 50
2 is assembled into the discharge passage 42, and only allows the discharge of air from the pump chamber 26. The suction valve also has the same structure as the discharge valve 44, and only allows air to flow into the pump chamber 26 from the suction passage.

Further, a flange portion 54 that extends outward in the radial direction is formed on the side of the rod 32 that is supported by the support hole 36.
One end portion of a rocker arm 56 as a swing arm is engaged with a portion of the flange portion 2 closer to the piston 18 than the flange portion 54 . This Rotsuka Arm 5
6 is rotatably attached to a pivot shaft 58 supported at both ends by the housing body 12, and is engaged with the rod 32 at a yoke portion 60 formed at one end thereof. The other end of the rocker arm 56 is formed to extend diagonally upward, and its tip is shaped like a yoke and supports both ends of the support shaft 62. This support shaft 6
2, an inner roller 64 is rotatably fitted to the inner roller 64, and an outer roller 66 is rotatably fitted to the outside of the inner roller 64.
The outer roller 66 is brought into contact with the outer circumferential surface of a cam 68 that is rotationally driven by the engine, that is, a cam surface 70 . The cam 68 is the camshaft 72
When this cam 68 is rotated, the outer roller 66 rotates and follows the cam surface 70, causing the rocker arm 56 to rotate around the pivot shaft 58. The piston 18 is oscillated within a certain angle range, and the piston 18 is moved forward and backward to suck in and discharge air. The direction of rotation of the outer roller 66 is determined such 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 has an axial hole 74 passing through its center in the axial direction.
is formed. The inner circumferential surfaces of the openings at both ends of the axial hole 74 are tapered surfaces with diameters increasing toward the opening side, and support is provided from the axial hole 74 in the axially intermediate portion of the peripheral wall of the support shaft 62. A pair of radial holes 76 are formed that extend to the outer circumferential surface of the shaft 62 and oppose the inner circumferential surface of the inner roller 64 . An annular protrusion 78 extending toward the center is further formed on the inner circumferential surface of the axial hole 74 at a position closer to one opening.

The camshaft 72 is rotatably supported between a cylinder head 82 of the engine and a cover 84 via a bush 80. The cylinder head 82 is formed with an oil passage 86 that supplies lubricating oil to the outer peripheral surface of the bush 80, and is branched from the oil passage 86 to the end face of the cylinder head 82 on the side facing the vacuum pump. An open nozzle 88 is formed. When the rocker arm 56 is at the bottom dead center, that is, the outer roller 66 is in contact with the surface of the cam surface 70 closest to the axis of the camshaft 72, the lubricating oil jet injected from the nozzle 88 is When the rocker arm 56 hits the open end of the axial hole 74 formed in the support shaft 62 and moves to the top dead center, that is, the position where the outer roller 66 contacts the surface of the cam surface 70 furthest from the axis of the camshaft 72. , are formed in a direction that covers the contact portion between the outer roller 66 and the cam 68. In this embodiment, the nozzle 88 constitutes a supply means for supplying lubricating oil.

The rocker arm 56 is formed with an oil guide hole 94 whose one end opens on the upper surface of the rocker arm 56 and the other end opens facing the outer peripheral surface of the pivot shaft 58. The oil guide hole 94 is opened at a position apart from the upper end of the outer circumferential surface of the pivot shaft 58, and the end thereof that opens on the upper surface of the rocker arm 56 is shaped like a funnel. The rocker arm 56 further has an oil guide groove 96 formed on its upper surface as an oil guide path, one end of which is close to the outer circumferential surface of the outer roller 66 and the other end of which is connected to the oil guide hole 94.
Further, an extremely shallow annular groove 98 is formed in the portion of the pivot shaft 58 where the oil guide hole 94 is opened, as shown exaggeratedly in FIG. Oil drain hole 1 that opens into the annular groove 98 and has the other end opened on the lower surface of the rocker arm 56
00 is formed.

In the vacuum pump configured as described above, during operation, lubricating oil jet is injected from the nozzle 88 in the direction shown by the two-dot chain line in FIGS. 68 mag. When the rocker arm 56 is at the bottom dead center, the lubricating oil jet is applied to the support shaft 62.
It hits the open end of the axial hole 74 formed in , and flows into the axial hole 74 . Since the opening end of the axial hole 74 has a tapered surface, lubricating oil easily flows into the axial hole 74, and the lubricating oil that flows in enters between the support shaft 62 and the inner roller 64 through the radial hole 76. , lubricates the outer peripheral surface of the support shaft 62 and the inner peripheral surface of the inner roller 64. At this time, since the protrusion 78 formed in the axial hole 74 obstructs the flow of lubricating oil, the lubricating oil is encouraged to flow into the radial hole 76, and the support shaft 62 and inner roller 64 are well lubricated. It will be done.

Furthermore, when the rocker arm 56 is at the top dead center, the lubricating oil jet injected from the nozzle 88 is applied to the contact portion between the outer roller 66 and the cam 68, and lubricates the contact surface between them. is rolled up by the rotation of the rotuka arm 5.
The lubricating oil that is sent to the upper side of the rocker arm 56 and falls onto the upper surface of the rocker arm 56 is guided to the oil guide groove 96 and flows into the oil guide hole 9.
4, the pivot shaft 58 and the rocker arm 5
6 and lubricates the sliding surfaces of both. The annular groove 98 formed on the outer circumferential surface of the pivot shaft 58 promotes the inflow and infiltration of lubricating oil, and the lubricating oil is evenly supplied to the sliding surface for good lubrication. Oil is discharged from the oil discharge hole 100.

In the case of a vacuum pump as in this embodiment, if lubricating oil is supplied to the sliding surfaces of the inner roller 64 and the support shaft 62, the ultimate vacuum degree can be improved. In piston type vacuum pumps,
If the inner roller 64, support shaft 62, etc. wear out,
The top dead center position of the piston 18 that is raised and lowered by the rocking of the rocker arm 56 rises, and the piston 18 of the housing 10 in which the piston 18 is housed
The piston 18 may collide with the portion facing the pump, causing abnormal noise, and the stroke of the piston 18 may be reduced, resulting in a decrease in pump function. If the top dead center position of the piston 18 is set low in order to avoid such problems, the volume of the top dead center of the pump chamber 26, that is, the volume of the pump chamber 26 when the piston 18 reaches the top dead center increases, and the vacuum Although the ultimate vacuum level of the pump was low, if the wear of the support shaft 62 etc. is reduced, the piston 18 and housing 1
This prevents abnormal noise from occurring due to collision with zero and deterioration of pump function. In addition, the piston 18 and the housing 1
Since there is no fear of interference with the pump chamber 26, the volume of the pump chamber 26 can be reduced, and the volume at the upper starting point of the pump chamber 26 is reduced, resulting in an effect of improving the ultimate degree of vacuum.

In the above embodiment, the rocker arm 56 is arranged to extend diagonally upward from the pivot shaft 58, but it may be extended in other directions such as horizontally. Even if this is done, the lubricating oil that has fallen onto the upper surface of the rocker arm can flow over the rocker arm and into the oil guide hole due to the change in attitude caused by the swinging of the rocker arm.

In addition, in the above embodiment, the rocker arm 5
Although a groove was formed on the upper surface of the rocker arm 56 to serve as the oil guide path, it does not necessarily have to be a groove. It can also be used as a road. Although it is desirable to provide an oil guide path in order to guide the oil that has fallen onto the rocker arm 56 to the oil guide hole 94, it is not necessary to provide it.

Furthermore, the lubricating oil jet hits the open end of the axial hole 74 and the contact portion between the outer roller 66 and the cam 68 not only when the rocker arm 56 is located at the bottom dead center and the top dead center, but also when the rocker arm 56 is located at the bottom dead center and the top dead center. roller 6
It is sufficient that the cam 6 hits the cam 68 at at least one position when the cam 6 follows the cam 68.

Furthermore, the supply means for supplying lubricating oil is not limited to a nozzle that injects lubricating oil jet from below to the rollers 64, 66, cam 68, etc.
Alternatively, lubricating oil may be dripped from above the cam 68 onto the contact portion thereof.

Although not illustrated in detail, the present invention can be implemented in various modifications and improvements based on the knowledge of those skilled in the art.

[Brief explanation of drawings]

FIG. 1 is a front sectional view showing a vacuum pump equipped with a swinging arm device, which is 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 a roller attached to the rocker arm and a cam with which the roller is brought into contact, together with a camshaft. 56... Locker arm, 58... Pivot axis,
62...Support shaft, 64...Inner roller, 66...Outer roller, 68...Cam, 70...Cam surface, 72...
...Camshaft, 74...Axis hole, 76...Radial hole, 82...Cylinder head, 88...Nozzle, 94...Oil guide hole, 96...Oil guide groove.

Claims (1)

[Claims for Utility Model Registration] A roller is rotatably attached to one end of a swinging arm that is rotatably supported by a support member via a pivot shaft, and the roller contacts the cam surface of the cam on its outer peripheral surface and rotates. In a swinging arm device of the type in which the swinging arm swings within a certain angle range by following a cam surface, the rotational direction of the roller can be determined by any one point on the outer circumferential surface of the roller. In accordance with this, the direction is determined so that the upper surface of the swing arm is approached from above, and the outer peripheral surface of the roller and the cam surface are determined in at least one position when the roller follows the cam surface. A supply means is provided for supplying lubricating oil to the contact portion with the swing arm, and the swing arm has one end opening on the top surface of the swing arm, and the other end opening between the outer circumferential surface of the pivot shaft and the shaft hole of the swing arm. 1. A lubricated swinging arm device, characterized in that an oil guide hole is formed in a gap between the swinging arm and the inner circumferential surface of the swinging arm, and the opening end on the upper surface side of the swinging arm is wider than other parts.