JP2594568Y2 - Reciprocating machine - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating machine suitable for use in, for example, a reciprocating compressor or a vacuum pump.

[0002]

2. Description of the Related Art FIG. 8 shows a reciprocating compressor as an example of a conventional reciprocating machine.

In FIG. 1, reference numeral 1 denotes a cylindrical cylinder, and 2 denotes a cylinder head mounted on the cylinder 1 via a valve plate 3. A chamber 2A and a discharge chamber 2B are formed. The valve plate 3 is provided with a suction hole 3A for communicating the suction chamber 2A with the inside of the cylinder 1, and a discharge hole 3B for communicating the discharge chamber 2B with the inside of the cylinder 1. A suction valve 4 is provided in the suction hole 3A, and a discharge valve 5 is provided in the discharge hole 3B.

[0004] Reference numeral 6 denotes a closed cylindrical piston provided in the cylinder 1 so as to be able to reciprocate in the axial direction. On the outer peripheral side of the upper part of the piston 6, ring grooves 6A in which piston rings 7, 7 are fitted are provided. A lower portion 6A is provided with a skirt portion 6B, and a middle portion is provided with a pair of boss portions 6C, 6C to which a piston pin 8 described later is attached. A pair of pin holes 6D, 6D extending in the radial direction of the piston 6 are formed in each of the boss portions 6C, and the pin holes 6D are arranged so as to oppose each other in the radial direction of the piston 6. .

Reference numeral 8 denotes each pin hole 6 of the piston at both ends in the axial direction.
D shows a piston pin fitted to the piston pin 8;
Is formed in a cylindrical shape from a high-rigidity material such as carbon steel, and has an outer diameter substantially equal to the inner diameter of each pin hole 6D of the piston 6. The piston pin 8 is connected to the piston 6 and the connecting rod 9 by inserting an upper end side of a connecting rod 9 described later into an axially intermediate portion thereof and press-fitting both end sides into the respective pin holes 6D. Is what you do.

Reference numeral 9 denotes a connecting rod whose upper end is rotatably connected to an intermediate portion in the axial direction of the piston pin 8 via a bearing 10. The lower end of the connecting rod 9 is a crankshaft (not shown).
And converts the rotation of the crankshaft into a reciprocating motion of the piston 6.

The reciprocating compressor according to the prior art has the above-described configuration. When the crankshaft is driven to rotate from the outside, the rotational force is transmitted to the piston 6 via the connecting rod 9, the piston pin 8, and the like. The piston 6 reciprocates in the cylinder 1. Then, due to the reciprocating motion of the piston 6, a gas such as air is sucked into the cylinder 1 via the suction valve 4, and this gas is compressed by the piston 6 in the cylinder 1 and discharged from the discharge valve 5.

When assembling the conventional reciprocating compressor, first, the upper end of the connecting rod 9 is positioned between the bosses 6C of the piston 6. Then, using a press machine or a special tool, the piston pin 8 is press-fitted into each pin hole 6D of the piston 6, and at this time, an intermediate portion of the piston pin 8 is Attach through.

[0009]

In the prior art described above, the piston pin 8 is inserted into each of the pin holes 6 of the piston 6.
By press-fitting the piston pin 8 into the pin hole 6D, both axial ends of the piston pin 8 are firmly fixed to the respective pin holes 6D in a detented state. For this reason, a press machine, a special tool, or the like must be used for the work of press-fitting the piston pin 8 into each pin hole 6D at the time of assembly and the work of removing the piston pin 8 from each pin hole 6D at the time of disassembly. In addition to the poor workability, there is a problem that the cost is increased due to the use of a press machine or a special tool.

As another prior art, as shown in FIG. 9, a set screw 2 is provided on each boss 6C of the piston 6.
A reciprocating compressor is known in which the piston pins 8 'are fixed to the respective pin holes 6D by providing the pins 1 and 21 and tightening the set screws 21. However, in such another conventional technique, when the piston pin 8 'is fixed in each pin hole 6D, or when the piston pin 8' is removed from each pin hole 6D, the piston pin 8 'is removed from the skirt portion 6B side of the piston 6. Tools such as a wrench and a screwdriver must be inserted into the piston 6 and each set screw 21 must be rotated.
There is a problem that tightening and removing each set screw 21 becomes very troublesome.

The present invention has been made in view of the above-mentioned problems of the prior art, and has a reciprocating mechanism that can easily fix a piston pin to a piston and greatly improve workability when assembling the piston pin. It is intended to provide a motive machine.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention adopts a feature that the piston pin has one end opening to the end face of the piston pin and the other end having the opening of the piston pin. A screw hole extending in the axial direction, a radial hole formed in a radial direction of the piston pin such that one end side is open to the outer peripheral surface of the piston pin, and the other end side communicates with the screw hole; A mooring member movably provided in the hole, and screwed into the screw hole from an end surface of the piston pin, and abutting the mooring member to push the mooring member toward the pin hole in the radial hole. And a movable screw member.

[0013]

According to the above construction, with the piston pin inserted into each pin hole of the piston, the screw member is tightened into the screw hole of the piston pin from the radial outside of the piston.
The mooring member abutting on the distal end side of the screw member is pushed toward the outer peripheral side of the piston pin in the radial hole. Then, the tip of the mooring member projects slightly from the outer peripheral side of the piston pin so that it can be strongly pressed around the pin hole of the piston. Can be.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A reciprocating compressor according to an embodiment of the present invention will be described below with reference to FIGS. In the embodiment, the same reference numerals are given to the same components as those in the conventional technique shown in FIG. 8 described above, and the description thereof will be omitted.

First, FIGS. 1 to 4 show a first embodiment of the present invention.

In the drawing, reference numeral 31 denotes a piston pin whose both ends in the axial direction are fitted into respective pin holes 6D of the piston 6, and the piston pin 31 is made of carbon steel or the like in substantially the same manner as the prior art piston pin 8 described above. The piston pin 31 is formed with a shaft hole 32 along the axis thereof although it is formed in a cylindrical shape with a high rigidity material. The outer diameter of the piston pin 31 is slightly smaller than the inner diameter of each pin hole 6D.

The shaft hole 32 of the piston pin 31 has screw holes 32A, 32A at both ends thereof.
2A is threaded with a female screw to which a fixing screw 36 described later is screwed. At the open end of each of the screw holes 32A, circular concave grooves 33, 33 are formed as counterbore holes, respectively, facing the end faces on both ends of the piston pin 31, and each of the concave grooves 33 will be described later. The head 36A of each fixing screw 36 is inserted.

Are pin holes 6 of the piston 6.
D shows small diameter radial holes formed at both ends of the piston pin 31 at positions corresponding to D, and the respective radial holes 34 are formed in the radial direction of the piston pin 31 and communicate with the respective screw holes 32A. doing. Each of the radial holes 34 is provided with a corresponding one of the screw holes 3.
The piston pins 31 are disposed so as to face each other in the radial direction of the piston pin 31 via 2A, and open to the outer peripheral surface of the piston pin 31 in each of the pin holes 6D.

Reference numerals 35, 35,... Denote small-diameter pins as mooring members slidably inserted into the respective radial holes 34 of the piston pin 31, and the small-diameter pins 35 are made of metal, ceramic or the like. The rigid material is formed with a dimension longer than each radial hole 34. Then, of both ends of each small diameter pin 35, the inner end 35A protrudes into the shaft hole 32, and the outer end 35B is pressed around each pin hole 6D of the piston 6, and the piston pin 31 is It is moored in the pin hole 6D in a detented state.

Reference numerals 36, 36 denote fixing screws as screw members screwed into the respective screw holes 32A of the shaft hole 32 from both ends of the piston pin 31, and the respective fixing screws 36 are as shown in FIGS. The head 36A has a large-diameter head 36A and a threaded portion 36B having a thread formed on the outer peripheral side. A conical abutment portion 36C is formed at the tip end of the threaded portion 36B. The abutment portion 36C of the fixing screw 36 has a conical outer peripheral surface abutting on the inner end 35A of each small-diameter pin 35, and pushes each small-diameter pin 35 in the arrow A direction (radial direction of the piston pin 31). To be pushed.

When the fixing screw 36 is tightened into the screw hole 32A as shown in FIG.
6C presses the inner end 35A of each small diameter pin 35 and pushes each small diameter pin 35 in each radial hole 34 in the direction of arrow A in FIG. Then, by tightening the fixing screw 36, the outer end 35B of each small-diameter pin 35 becomes a pin hole 6D of the piston 6.
When it comes into strong contact with the periphery, each small diameter pin 35 is anchored around the pin hole 6D of the piston 6, so that the piston pin 31 is fixed in the pin hole 6D in a detented state and a retaining state. Become. When the fixing screw 36 is tightened by the screw hole 32A of the shaft hole 32, the head 36A of the fixing screw 36 is
So that it does not protrude radially from the outer periphery of the piston 6.

On the other hand, in a state where the fixing screw 36 is rotated in a direction to loosen from the screw hole 32A, the fixing screw 36 moves in the direction of arrow B in FIG. Then, the frictional contact state with the contact portion 36C is released, and each small-diameter pin 35 can be moved by its own weight in each radial hole 34. Then, the outer end 35B of each small diameter pin 35 is released from the mooring state around the pin hole 6D of the piston 6, and the piston pin 31 can be pulled out from the inside of the pin hole 6D.

The reciprocating compressor according to the present invention has the above-described configuration, and its basic operation is not particularly different from that of the prior art.

Next, the operation of assembling the reciprocating compressor according to this embodiment will be described.

First, the upper end of the connecting rod 9 is located between the bosses 6C of the piston 6. Then, with the fixing screws 36 loosened, the piston pin 31 is inserted from the radial outside of the piston 6 in the order of one pin hole 6D, the bearing 10 of the connecting rod 9, and the other pin hole 6D. .

Next, each fixing screw 36 of the piston pin 31 is tightened from the outer peripheral side of the piston 6 using a tool such as a wrench, a screwdriver, or the like, and each small diameter pin 35 is pushed in each radial hole 34 so as to be pressed. The piston pin 31 is fixed in the pin hole 6D in a detented state and a retaining state.

Thus, in this embodiment, the piston pin 3
1, a shaft hole 32 having screw holes 32A, 32A at both ends is formed, and radial holes 34 communicating with the screw holes 32A and opening on the outer peripheral side of the piston pin 31 are formed. In the state where each small diameter pin 35 is slidably inserted in the direction hole 34, each fixing screw 36 is tightened in each screw hole 32A so that each small diameter pin 35 is pushed in the direction of arrow A. Therefore, when assembling the piston pins 31 into the respective pin holes 6D of the piston 6, the piston pins 31 can be easily inserted into the respective pin holes 6D with the fixing screws 36 being loosened. If each fixing screw 36 is tightened from the outer peripheral side, each small diameter pin 35 can be pressed around each pin hole 6D of the piston 6 and can be strongly moored, whereby the piston pin 31 can be inserted into each pin hole 6D. Detent And it can be fixed to the retaining state.

Therefore, in this embodiment, the piston pin 31
Inserting the piston pin 31 into each pin hole 6D or extracting the piston pin 31 from each pin hole 6D is performed by a press machine,
It can be easily performed without using special tools, etc., greatly improving the workability of assembling and disassembling the piston pin 31. In addition, there is no need to use a press machine, special tools, etc., and the manufacturing cost is reduced. And increase productivity.

When the piston pin 31 is fixed in each pin hole 6D, or when the piston pin 31 is removed from each pin hole 6D, each fixing screw 36 of the piston pin 31 is wrenched from the radial outside of the piston 6. It is only necessary to rotate using a tool such as a screwdriver. This allows
It is not necessary to insert a tool such as a wrench or a screwdriver into the piston 6 from the skirt portion 6B side of the piston 6 and rotate each set screw 21 as in the other prior art described above. The work of assembling or removing the pin 31 can be easily performed.

Next, FIG. 5 shows a second embodiment of the present invention, which is characterized in that the end of the mooring member is formed in a spherical shape. In this embodiment, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof will be omitted.

In the figure, reference numerals 41, 41 denote small-diameter pins as mooring members slidably inserted into respective radial holes 34 of the piston pin 31. Each of the small-diameter pins 41 is a first embodiment. Are formed in substantially the same manner as the small diameter pins 35 described in
Both ends are an inner end 41A and an outer end 41B, respectively.
However, each of the small-diameter pins 41 is
The tip surface of A is formed in a hemispherical shape. The inner end portion 41A abuts on the abutment portion 36C of the fixing screw 36 with a relatively large contact area, so that the inner end portion 41A can be smoothly pushed in the arrow A direction in each radial hole 34 of the piston pin 31. Has become.

In this embodiment configured as described above, the same operation and effect as those of the first embodiment can be obtained.
Particularly, in this embodiment, since the inner end 41A of each small diameter pin 41 is formed in a hemispherical shape, the contact portion 36 of each fixing screw 36 is formed.
C can relatively smoothly abut against the inner end 41A of each small-diameter pin 41, and when each fixing screw 36 is tightened, each small-diameter pin 41 is smoothly moved in the direction of arrow A in each radial hole 34. And each fixing screw 3
6 can be prevented from being damaged by frictional contact with the inner end 41A of each small-diameter pin 41, and the life can be extended.

Next, FIG. 6 shows a third embodiment of the present invention. The feature of this embodiment is that the mooring member is formed by a spherical steel ball or the like, and a high rigidity is imparted to the mooring member. I did it. In the figure, reference numeral 51 denotes a piston pin whose both ends in the axial direction are inserted into the respective pin holes 6D of the piston 6, and the piston pin 51 is formed substantially in the same manner as the above-described conventional piston pin 8. And the piston pin 5
A shaft hole 52 whose both ends are screw holes 52A (only one side is shown) is formed in the axial direction, and a concave groove 53 (only one side is shown) that is a counterbore is formed on both end surfaces of the piston pin 51. Have been.

Numerals 54, 54 indicate positions corresponding to the respective pin holes 6D of the piston 6, and radial holes formed in both ends of the piston pin 51 in the radial direction.
Each of the radial holes 54 is formed in substantially the same manner as each of the radial holes 34 described in the first embodiment,
Is formed to have a relatively large inner diameter in order to accommodate the.

Numerals 55 and 55 denote balls as mooring members disposed in the respective radial holes 54 so as to be movable in the radial direction.
Each ball 55 is formed in a spherical shape from a metal material having high wear resistance, such as steel, or a ceramic material, for example, and its outer dimension corresponds to the inner diameter of the radial hole 54. Each ball 55 is connected to a contact portion 5 of a fixing screw 56 described later.
6C, the piston pin 51 is pushed around the pin hole 6D of the piston 6 by being pushed in the radial direction C in each radial hole 54, and the piston pin 51 is moored to the pin hole 6D with high rigidity. I have.

Reference numeral 56 denotes a fixing screw (only one side is shown) as a screw member screwed into each screw hole 52A of the shaft hole 52. The fixing screw 56 is substantially the same as the fixing screw 36 of the first embodiment. , A large-diameter head portion 56A, a screw portion 56B having a thread formed on the outer peripheral side, and a conical contact portion 56C, and the contact portion 56C is in contact with each ball 55.
The contact portion 56C of the fixing screw 56 pushes each of the balls 55 in the direction of arrow C by tightening the fixing screw 56 so that each of the balls 55 comes into strong contact with the periphery of the pin hole 6D. Has become.

In this embodiment constructed as described above, substantially the same operation and effect as in the second embodiment can be obtained. In this embodiment, in particular, each ball 5 is provided in each radial hole 54.
Since the ball 5 is disposed, high rigidity can be given to each of the spherical balls 55, and each ball 55 is strongly contacted with the contact portion 56C of the fixing screw 56 and the periphery of the pin hole 6D of the piston 6. Thus, each ball 55 can be firmly moored around the pin hole 6D of the piston 6. Further, a contact portion between the contact portion 56C of the fixing screw 56 and each ball 55, each ball 55
In the contact portion between the ball 55 and the radial hole 54 and the contact portion between the pin hole 6D and each ball 55, the respective portions can be reliably prevented from being worn or damaged early, and the service life can be extended. Can be.

FIG. 7 shows a fourth embodiment of the present invention. In this embodiment, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof will be omitted.

The present embodiment is characterized in that one end of each of the piston pins 61 communicates with each screw hole 62A (only one side is shown), and the other end of the piston pin 61 opens on the outer peripheral surface of the piston pin 61. , And each small-diameter pin 6 as a mooring member is formed in each of the radial holes 63.
4 is slidably inserted.

The piston pin 61 is formed substantially similarly to the piston pin 31 described in the first embodiment.
Both ends of the shaft hole 62 are screw holes 62A. Also,
Each radial hole 63 is formed in the circumferential direction of the piston pin 61 at an interval of, for example, about 120 degrees. And
Each small-diameter pin 64 has its inner end 64A pressed by the abutting portion 36C of the fixing screw 36, and is pushed in each radial hole 63 toward the outer peripheral side of the piston pin 61, and its outer end 64B has its pin hole 6D Is strongly abutted at three places (equal intervals) around the periphery of the body.

In this embodiment constructed as described above, substantially the same operation and effect as those of the above embodiments can be obtained.
In particular, in the present embodiment, three radial holes 63 are respectively formed on both end sides of the piston pin 61 (a total of six holes), and the small diameter pins 64 are slidably inserted into the respective radial holes 63. Therefore, by tightening the fixing screw 36, each small-diameter pin 64 is pushed to the outer peripheral side of the piston pin 61,
The outer end 64B of each small-diameter pin 64 can be brought into contact with the periphery of each pin hole 6D at three places at equal intervals, and the piston pin 61 is positioned and fixed so as to be automatically centered within the pin hole 6D. be able to.

Therefore, even if the outer diameter of the piston pin 61 is slightly smaller than the inner diameter of the pin hole 6D, the positioning action of each small diameter pin 65 causes the piston pin 61 to be accurately positioned on the central axis in the pin hole 6D. The pin hole 6D and the piston pin 61 can have a large dimensional tolerance, and the degree of freedom in design can be increased.

In each of the above embodiments, the piston pin 3
1 (51, 61), the axial hole 32 (52, 52) penetrating in the axial direction.
62) is formed, and screw holes 32A (52A, 62A) are formed at both ends of the shaft hole 32 (52, 62). In the present invention, the shaft hole 32 (52, 62) is formed. Alternatively, for example, left and right screw holes may be formed at both end surfaces of the piston pin and extend to the axial center of the piston pin.

In each of the above embodiments, a reciprocating compressor is described as an example of a reciprocating machine. However, the present invention is not limited to this, and may be applied to a reciprocating machine such as a vacuum pump. it can.

[0045]

According to the present invention as described in detail above, according to the present invention, each screw hole extending in the axial direction of the piston pin and opening at the end face of the piston pin is formed, and communicates with each screw hole.
Each screw which formed each radial hole opened in the outer peripheral surface of the piston pin, and which screwed each mooring member movably provided in each radial hole from the end face of the piston pin to each screw hole. By pushing with a member, the piston pin is moored in each pin hole of the piston, so that with each screw member loosened, the piston pin can be easily inserted into each pin hole of the piston, and then By tightening each screw member from the outside in the radial direction of the piston, each mooring member can be strongly moored around each pin hole, and the piston pin can be fixed in each pin hole in a detented state and pulled out state. . Therefore, the work of mounting and disassembling the piston pin can be easily performed without using a dedicated assembling device or the like, and the workability in mounting and disassembling the piston pin can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a piston and a connecting rod of a reciprocating compressor according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing a main part in FIG.

FIG. 3 is a sectional view similar to FIG. 2, showing a state in which a fixing screw is loosened.

FIG. 4 is a sectional view taken in the direction of arrows IV-IV in FIG. 2;

FIG. 5 is a sectional view similar to FIG. 2, showing a second embodiment of the present invention;

FIG. 6 is a sectional view similar to FIG. 2, showing a third embodiment of the present invention.

FIG. 7 is a sectional view similar to FIG. 4, showing a fourth embodiment of the present invention;

FIG. 8 is a longitudinal sectional view showing a conventional reciprocating compressor.

FIG. 9 is a vertical sectional view showing a piston and a connecting rod of another conventional reciprocating compressor.

[Explanation of symbols]

 1 Cylinder 6 Piston 6C Boss 6D Pin Hole 9 Connecting Rod 31, 51, 61 Piston Pin 34, 54, 63 Radial Hole 35, 41, 64 Small Diameter Pin (Mooring Member) 35A, 41A, 64A Inner End 35B, 41B , 64B Outer end 36, 56 Fixing screw (screw member) 36C, 56C Contact part 55 Ball

Claims (1)

(57) [Scope of request for utility model registration] 1. A piston having a pair of pin holes extending in a radial direction and reciprocally provided in a cylinder, a piston pin having both axial ends located in respective pin holes of the piston, and a piston pin interposed therebetween. In the reciprocating machine comprising a connecting rod rotatably connected to the piston, one end of the piston pin is opened at an end face of the piston pin, and the other end extends in the axial direction of the piston pin. A screw hole, a radial hole formed in the radial direction of the piston pin such that one end side is open to the outer peripheral surface of the piston pin, and the other end side communicates with the screw hole, and is movable in the radial hole. A mooring member provided, and a screw member screwed into the screw hole from an end face of the piston pin and pushing the mooring member toward the pin hole in the radial hole by abutting on the mooring member. Be prepared Reciprocating machine.