JPH0341104Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a locking piston type air compressor that is suitably used for supplying compressed air to, for example, a vehicle height adjustment device.

[Conventional technology]

This type of air compressor, which was previously filed by the applicant as Utility Model Application No. 1983-94273 (hereinafter referred to as prior art), is shown in FIGS. 5 and 6.

In the figure, reference numeral 1 denotes a crankcase with a crank chamber A defined therein, and an intake port 2 for sucking outside air into the crank chamber A is formed at the lower end of the crankcase 1. A crankshaft 3 located in the crank chamber A and connected to the output shaft of the motor (none of which is shown);
A balance weight 4 fixed to is provided.

5 is a cylindrical cylinder mounted on the crankcase 1 in communication with the crank chamber A;
A cylinder head 6 is hermetically fixed to the upper end of the cylinder 5. Here, the cylinder head 6
A screw accommodating portion 6A is recessed on the lower surface side, and a cylindrical plug mounting portion 6B is protruded from the upper surface side, and the plug insertion portion 6B and screw accommodating portion 6A are connected to the The discharge holes 7 communicate with each other. Reference numeral 8 denotes a plug screwed onto the plug insertion portion 6B, and a discharge passage 9 is formed between the plug 8 and the plug insertion portion 6B.
It communicates with a discharge port (not shown). Reference numeral 10 indicates a discharge valve located between the discharge passage 9 and the discharge hole 7 so as to be seated on and off the discharge hole 7, and the discharge valve 10 is stretched between it and the plug body 8. It is constantly urged onto the discharge hole 7 by a compression spring 11.

Next, 12 is a disk-shaped locking piston with a piston rod 13 integrally provided at the center of the lower surface, and a circular or rectangular convex portion 12A is provided on the upper surface side of the locking piston 12 at a predetermined height. The outer peripheral side of the protrusion 12A becomes a flat holding part receiving surface 12B, and the inner side thereof is provided with a substantially rectangular recess 12C having a predetermined depth. A stepped cylindrical screw seat 12D is protrudingly formed in the recess 12C, located on the right side in the figure, and a stepped portion 12E of the screw seat 12D is disposed at the same height position as the convex portion 12A. (See Figure 2).
Further, a plurality of small-diameter intake holes 14 are bored at the bottom side of the recess 12C, located toward the left side in the figure, and each intake hole 14 is in continuous communication with the crank chamber A.

The locking piston 12 is constructed as described above, and is rotatably connected to the crankshaft 3 via a bearing 15 provided at the lower end of the piston rod 13. As the crankshaft 3 rotates, it swings and reciprocates within the cylinder 5 via the piston rod 13, forming a compression chamber B between it and the cylinder head 6.

Reference numeral 16 denotes a ripple ring formed of a highly wear-resistant resin material such as polytetrafluoroethylene (Teflon), and the ripple ring 16 is connected to a locking piston 12 and a fixing ring 1 to be described later.
An annular flat plate-shaped clamping portion 16A fixed between the
and a seal portion 16B that rises from the outer circumferential side of the holding portion 16A and comes into sliding contact with the inner circumferential surface of the cylinder 5.

17 is a fixing ring for holding the ripple ring 16 between the locking piston 12;
Like the locking piston 12, the fixing ring 17 is made of a metal material and is shaped like a disk.
An annular protrusion 17A is provided on the outer peripheral side of the lower surface of the protrusion 1.
It is formed with an inner diameter corresponding to the outer diameter of 2A, and the flat lower surface serves as a clamping part pressing surface 17B. Further, a plurality of intake holes 18 are bored in the axial direction near the annular protrusion 17, and a mounting hole 17C is provided at an eccentric position on the right side in the figure to fit into the small diameter side of the screw seat 12D. is drilled. The fixing ring 17 formed as described above is attached to the mounting hole 1.
7C is fitted onto the small diameter side of the screw seat 12D and is fastened to the stepped portion 12E with the screw 19.
Then, by tightening the fixing ring 17 to the stepped portion 12E with the screw 19, the fixing ring 17
The annular protrusion 17A fits into the outer peripheral side of the protrusion 12A of the locking piston 12, and the locking piston 1
The clamping portion 16A of the ripple ring 16 is firmly held between the fixing ring 17 and the concave portion 12C of the locking piston 12, and a valve chamber 20 that communicates with the intake hole 14 and the other intake hole 18 is formed between the fixing ring 17 and the recess 12C of the locking piston 12. are doing.

Further, reference numeral 21 denotes an intake valve disposed within the valve chamber 20 so as to be seated in and out of each intake hole 14 of the locking piston 12, and the intake valve 21 is made of a flexible resin such as rubber or soft synthetic resin. Depending on the material, the recess 1
It is formed into a substantially rectangular shape slightly smaller than 2C. The base end side thereof is fitted into the large diameter side of the screw seat 12D, and is fixed with a screw 19 via a fixing ring 17. In addition, the intake valve 2
The distal end side of the air pump 1 is formed to be slightly thinner than the proximal end side, and an oval annular protrusion 21A is protruded from the lower surface side so as to surround the intake port 14. On the other hand, the upper surface of the intake valve 21 and the fixing ring 1
The gap S formed between the intake valve 21 and the intake valve 7 regulates the lift height when the intake valve 21 is opened, and prevents a closing delay when the intake valve 21 is closed.

According to the prior art, an air compressor has the construction as described above, and its operation will now be described.

First, when the crankshaft 3 is rotationally driven by the output shaft of the motor, the locking piston 12 is reciprocated while being oscillated within the cylinder 5 by the crankshaft 3. In the suction process in which the locking piston 12 reaches from the top dead center to the bottom dead center, the compression chamber B
Since the inside becomes negative pressure, the intake valve 21 opens, and the air in the crank chamber A is sucked into the compression chamber B via the intake hole 14, the valve chamber 20, and another intake hole 18. On the other hand, in the compression process in which the locking piston 12 reaches from the bottom dead center to the top dead center, the intake valve 21 is closed and the air in the compression chamber B is compressed. When the pressure in the compression chamber B reaches a predetermined pressure, the discharge valve 10 opens against the spring force of the spring 11, and the compressed air flows from the discharge hole 7 to the discharge port side via the discharge passage 9. It is discharged and stored in an air tank via an air dryer.

[Problem that the invention attempts to solve]

According to the prior art described above, a valve chamber 20 is formed between the locking piston 12 and the fixed ring 17, and the intake valve 2 made of flexible resin is disposed within the valve chamber 20.
1, it is possible to improve the sealing performance when closing the valve, reduce the tapping noise when opening and closing the valve, and prevent delays in closing by regulating the lift height of the intake valve 21. It can be effective.

By the way, in the prior art, the clamping part receiving surface 12B of the locking piston 12 which clamps and fixes the ripple ring 16 and the clamping part pressing surface 1 of the fixing ring 17
7B are both formed as flat surfaces, so when the ripple ring 16 is sandwiched between the locking piston 12 and the fixing ring 17 and the screw 19 is tightened, the tightening force of the screw 19 is equal to the ripple ring 16. Holding part pressing surface 17B with a large pressing area against
On the other hand, the fixing ring 17 is fastened to the locking piston 12 without a sufficient tightening force acting on the screw seat 12D of the locking piston 12.

On the other hand, since both the locking piston 12 and the fixing ring 17 that sandwich the synthetic resin ripple ring 16 are made of metal, the ripple ring 16
changes over time, the tightening force of the screw 19 applied to the ripple ring 16 via the clamping part pressing surface 17B of the fixing ring 17 becomes weaker, and the ripple ring 16
There is a problem that a gap is created between the locking piston 12 and the locking piston 12, and compressed air leaks to the crank chamber A side. In addition, as described above, since the fixing ring 17 is not fastened with sufficient tightening force to the screw seat 12D of the locking piston 12, as the ripple ring 16 deforms, the clamping part pressing surface 17B of the fixing ring 17 If the tightening force on the side is weakened, the screw 19
There is an unresolved problem that the screw may become loose and fall off the screw seat 12D, damaging other parts.

The present invention was developed in view of the problems of the prior art described above, and it prevents the tightening force of the fixing ring by the screw from weakening due to the deformation of the ripple ring, and also prevents the leakage of compressed air due to the deformation of the ripple ring. The purpose of the present invention is to provide an air compressor with excellent sealing performance and durability.

[Means for solving problems]

The means of the present invention adopted to solve the above-mentioned problems consists of a cylinder having a cylinder head mounted on a crankcase, a cylinder connected to a crankshaft in the crankcase, and a cylinder that swings within the cylinder. a locking piston that reciprocates and forms a compression chamber between the locking piston and the cylinder head; an annular and flat clamping part provided on the locking piston; and a fixing ring that fixes the gripping part of the lip between the locking piston and the locking piston. The present invention is characterized in that an annular raised portion is formed which annularly holds the gripping portion of the ripple ring between it and the other.

[Effect]

An annular protuberance is formed on either the locking piston or the fixed ring to reduce the pressing area against the gripping part of the ripple ring, so the tightening force of the screw presses the ripple ring and firmly attaches the fixed ring to the locking piston. As a result of being able to act on the side to be tightened, even if the ripple ring is deformed, the tightening force of the screw does not weaken, and the fixing ring is reliably tightened.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to FIGS. 1 to 4. Note that the same reference numerals are given to the same components as those of the prior art described above, and the explanation thereof will be omitted.

1 and 2 show a first embodiment of the invention.

31 in the figure is a locking piston in which a piston rod 32 is integrally formed in the center of the lower surface, and a circular or rectangular convex portion 31A is formed on the upper surface side of the locking piston 31. Part 3
The outer peripheral side of 1A becomes a flat holding part receiving surface 31B, and a substantially rectangular recess 31C is formed on the inner side. Further, a stepped cylindrical screw seat 31D is formed in the recessed portion 31C to protrude from the convex portion 31C, and is located on the right side in the figure.
It is the same as the prior art in that it is placed at the same height as A (see Figure 4), but
The difference is that the holding portion receiving surface 31B is provided with an annular groove 33 having a substantially semicircular cross section corresponding to an annular protrusion 35 to be described later.

On the other hand, the reference numeral 34 denotes a fixing ring made of a metal material and formed into a disk shape like the fixing ring 17 according to the prior art. It is the same as the prior art in that a mounting hole 34B that fits into the screw seat 31D of the king piston 31 is bored, but an annular groove of the locking piston 31 is formed on the lower surface side of the annular protrusion 34A. The difference is that an annular protrusion 35 having a substantially semicircular cross section corresponding to 33 is provided around the periphery.

The air compressor according to this embodiment has the configuration as described above, and its basic configuration is not particularly different from that of the prior art.

However, in this embodiment, the locking piston 31
An annular groove 33 is provided on the holding surface 31B of the holding ring 34, and an annular protrusion 35 corresponding to the annular groove 33 is provided on the lower surface of the annular protrusion 34A of the fixing ring 34. As a result, the ripple ring 16 is sandwiched between the locking piston 31 and the fixed ring 34,
When the fixing ring 34 is tightened with the screw 19, the annular protrusion 35 of the fixing ring 34 first comes into contact with the clamping portion 16A of the ripple ring 16. As the screw 19 is screwed in, the fixing ring 3
4 is pressed against the intake valve 21 side, and the annular protrusion 35 is pressed against the gripping portion 16A of the ripple ring 16.
It is pressed so that it bites into the body. At this time, the locking piston 31 is fitted into the annular groove 33 side of the locking piston 31 via the clamping part 16A, and since the pressing area against the ripple ring 16 is smaller than that of the prior art, the annular protrusion 35 of the fixing ring 34 The clamping force of the screws 19 on the sides is small compared to the prior art.

When the screw 19 is further tightened, a screw 1 is attached to the upper end surface of the screw seat 31D of the locking piston 31.
9 is in contact with the fixing ring 34, and the fixing ring 34 is in the mounting hole 3.
It is fixed under the tightening force at the edge of 4B. This tightening force is then propagated in the axial direction of the fixing ring 34, causing the annular protrusion 34 of the fixing ring 34 to
As a result of the annular protrusion 35 holding the ripple ring 16 in a state where it is slightly pushed into the annular groove 33 of the locking piston 31 with a gap left between A and the ripple ring 16, the ripple ring 16 is deformed. Also, leakage of compressed air from between the ripple ring 16 and the locking piston 31 can be reliably prevented.

Moreover, the annular protrusion 35 provided on the fixing ring 34
The pressing area of is made small, and most of the tightening force of the screw 19 is applied to tighten the fixing ring 34 to the screw seat 31D of the locking piston 31, so that the ripple ring 16 is not deformed. Even in this case, it is possible to prevent the tightening force of the screw 19 from weakening and falling off from the locking piston 31 as in the prior art.

In the embodiment, the locking piston 31 is provided with an annular groove 33, and the fixing ring 34 is provided with an annular protrusion 3.
5, but on the contrary, an annular protrusion is provided on the locking piston 31, and the locking piston 31 is provided with an annular protrusion.
3 may be provided with an annular groove.

Next, FIG. 3 shows a second embodiment of the present invention.
Note that in this embodiment and a third embodiment described later, the same components of the prior art described above are denoted by the same reference numerals, and the explanation thereof will be omitted.

41 in the figure is a locking piston in which a piston rod 42 is integrally formed in the center of the lower surface, and the upper surface side of the locking piston 41 has a convex portion 41A similar to that in the prior art, and a holding surface. 41B, recess 41C, screw seat 41D, screw seat 4
1D are respectively provided, and furthermore, in the center of the width direction of the holding part receiving surface 41B, there is an annular ridge having a substantially semicircular cross section for annularly holding the holding part 16A of the ripple ring 16. Part 43
is formed protrudingly.

With this configuration, the pressing area of the locking piston 41 against the ripple ring 16 can be reduced, and a screw 1 is provided on the outer circumferential side of the fixing ring 17.
It is possible to prevent the tightening force of No. 9 from acting too strongly.

Furthermore, FIG. 4 shows a third embodiment of the present invention.
This embodiment is characterized by an annular raised portion 5 having a convex curved pressing surface 52A on the outer peripheral side of the lower surface of the fixing ring 51.
2 is integrally formed, and by configuring it in this way, it is possible to obtain the same effect as the second embodiment described above.

[Effect of idea]

As detailed above, according to the present invention, either the locking piston or the fixed ring is provided with an annular protuberance that annularly holds the ripple ring between the locking piston and the other, so that the pressing area against the ripple ring is reduced. Therefore, the tightening force of the screw that fastens the fixing ring to the locking piston acts more on the fixing ring than on the ripple ring. Therefore, even if the ripple ring is deformed and the pressing action of the fixing ring is reduced, it is possible to prevent the fixing ring from shaking due to loosening of the screws. Furthermore, since the annular protrusion is pressed into contact with the ripple ring, leakage of compressed air can be reliably prevented and the volumetric efficiency of the air compressor can be improved.

[Brief explanation of drawings]

1 and 2 show a first embodiment of the present invention, FIG. 1 is a longitudinal sectional view of an air compressor, and FIG.
The figure is an enlarged view of the main part in Fig. 1, Fig. 3 is an enlarged view of the main part showing the air compressor according to the second embodiment in the same way as Fig. 2, and Fig. 4 is an enlarged view of the main part according to the third embodiment. 5 and 6 show the prior art, FIG. 5 is a vertical cross-sectional view of the air compressor, and FIG. 6 is an enlarged view of the main parts shown in FIG. It is an enlarged view of the main part. 1...Crankcase, 5...Cylinder, 6...
...Cylinder head, 16...Rip ring, 3
1,41... Locking piston, 34,51...
...fixing ring, 35, 43, 52... annular protrusion.

Claims (1)

[Scope of utility model registration request] A cylinder having a cylinder head mounted on a crankcase is connected to a crankshaft in the crankcase, moves reciprocatingly while rocking within the cylinder, and forms a compression chamber between the cylinder head and the cylinder head. a locking piston, a ripple ring provided on the locking piston and comprising an annular flat plate-shaped clamping part and a lip part rising from the outer peripheral side of the clamping part and slidingly contacting the inner peripheral surface of the cylinder; a fixing ring that fixes the clamping part of the ripple ring between the piston and the locking piston and the fixing ring; An air compressor formed by