WO2017022716A1

WO2017022716A1 - Piston assembly and reciprocating compressor provided with same

Info

Publication number: WO2017022716A1
Application number: PCT/JP2016/072522
Authority: WO
Inventors: 巌内門
Original assignee: サンデン・エンバイロメントプロダクツ株式会社
Priority date: 2015-08-04
Filing date: 2016-08-01
Publication date: 2017-02-09
Also published as: JP2017031915A

Abstract

This piston assembly 10 is provided with a piston 44, a piston pin hole 46, a piston pin 28, a fixing pin 48, a piston-side fixing pin hole 50, and a piston-pin-side fixing pin hole 52. The piston pin 28 has, on an end surface 64 exposed from the piston pin hole 46: a hole direction clarification part 68 through which the hole direction of the piston-pin-side fixing pin hole 52 is clarified; and a rotation adjustment part 68 for rotating and positioning the piston pin 28 on the basis of the hole direction clarification part 68, so that the piston-pin-side fixing pin hole 52 is aligned with the piston-side fixing pin hole 50.

Description

Piston assembly and reciprocating compressor provided with the same

The present invention relates to a piston assembly and a reciprocating compressor including the same.

As disclosed in, for example, Patent Document 1, this type of piston assembly is disposed in a hermetic container of a hermetic reciprocating compressor and includes a piston having a skirt portion, and a piston pin hole penetrating the skirt portion. The piston pin is inserted through the piston pin hole, and a locking pin (hereinafter referred to as a fixing pin) for fixing the piston pin to the skirt portion is provided. A similar piston assembly is also disclosed in US Pat.
In this piston assembly, the piston side fixing pin hole is penetrated through the skirt portion from the end surface of the skirt portion to the piston pin hole. The fixing pin is inserted into the piston side fixing pin hole. The piston pin is formed with a piston pin side fixing pin hole into which the fixing pin inserted into the piston side fixing pin hole is press-fitted and fixed, for example.

Further, the reciprocating compressor disclosed in Patent Document 1 includes a piston assembly, a crankshaft having a main shaft portion and a crankpin, a frame that rotatably supports the main shaft portion, and a piston that is slidably fitted. A cylinder block having a cylinder bore to be combined, and a connecting rod having a large end (one end) connected to the crank pin and a small end (other end) connected to the piston pin are provided.

Japanese Utility Model Publication 1-17662 JP 2002-243038 A

When assembling the piston assembly having the above-described structure, unless the piston pin side fixing pin hole is in a consistent state with the piston side fixing pin hole, fixing pins are attached to the piston pin side fixing pin hole and the piston side fixing pin hole. Can't insert. However, if the piston pin side fixed pin hole and the piston side fixed pin hole are misaligned with the piston pin inserted through the piston pin hole, check the hole direction of the piston pin side fixed pin hole formed on the piston pin. I can't.

In addition, conventionally, no special consideration has been given to the means for matching the piston pin side fixing pin hole with the piston side fixing pin hole, so it is not possible to match the piston pin side fixing pin hole with the piston side fixing pin hole. Have difficulty.
In addition, when the piston is at the bottom dead center position, the piston pin and the piston pin hole are covered with the cylinder block, so that the work of matching the piston pin side fixing pin hole with the piston side fixing pin hole is more difficult. Become.

Also, in the sealed container, the crankshaft axial direction and the piston sliding direction intersect each other substantially orthogonally, and the frame and cylinder block are formed separately. Therefore, when the cylinder block is fastened to the frame with bolts, it is necessary to secure the wall thickness that is fastened to the cylinder block, and compression is performed by the weight of the bolt and the fastening wall thickness and the fastening amount of the cylinder block. The weight reduction and downsizing of the machine were hindered.

The present invention has been made based on the above-described circumstances, and an object of the present invention is to provide a piston assembly that is excellent in assemblability, can realize weight reduction and downsizing, and a reciprocating compressor including the same. There is to do.

In order to achieve the above object, a piston assembly according to the present invention includes a piston having a skirt portion forming a hollow portion, a piston pin hole penetrating the skirt portion, a piston pin inserted through the piston pin hole, and a skirt. A fixed pin for fixing the piston pin to the part, a piston side fixed pin hole that is penetrated from the end face of the skirt part to the piston pin hole and the fixed pin is inserted, and is formed in the piston pin, and is inserted into the piston side fixed pin hole A piston pin-side fixing pin hole into which the fixed pin inserted is inserted, and the piston pin has, on the end surface exposed from the piston pin hole, a hole direction clearly indicating portion indicating the hole direction of the piston pin-side fixing pin hole; Based on the hole direction indication part, the piston pin is rotated and positioned so that the piston pin side fixing pin hole matches the piston side fixing pin hole. And a rotation adjusting unit for.

Preferably, the piston pin has, on its end surface, a long groove parallel to the hole direction of the piston pin-side fixed pin hole as a hole direction indicating portion and a rotation adjusting portion.
A reciprocating compressor according to the present invention includes a piston assembly according to claim 1, a crankshaft having a main shaft portion and an eccentric shaft portion, a frame for rotatably supporting the main shaft portion, and one end portion being eccentric. A connecting rod connected to the shaft and having the other end connected to the piston pin; and a cylinder block having a cylinder bore into which the piston assembly is slidably fitted. The frame and the cylinder block are integrally formed so as to intersect with the moving direction.

Preferably, the cylinder block has a notch that exposes the end face of the piston pin from the cylinder bore when the piston assembly is at the bottom dead center position.
Preferably, the end surface of the piston pin has an arc shape along the inner wall of the cylinder bore.

According to the present invention, the piston pin is inserted through the piston pin hole by having the hole direction indicating portion that clearly indicates the hole direction of the piston pin side fixing pin hole on the end surface exposed from the piston pin hole. When the piston pin side fixing pin hole and the piston side fixing pin hole are shifted in the state, the hole direction of the piston pin side fixing pin hole formed in the piston pin can be confirmed.

The piston pin is positioned on the end surface exposed from the piston pin hole by rotating the piston pin so that the piston pin side fixing pin hole is aligned with the piston side fixing pin hole based on the hole direction clearly defining portion. By rotating the piston pin based on the hole direction clearly defining portion, it is possible to easily make the piston pin side fixed pin hole consistent with the piston side fixed pin hole. it can. Therefore, the assemblability of the piston assembly and the reciprocating compressor can be greatly improved.

It is a longitudinal cross-sectional view of the reciprocating compressor which concerns on one Example of this invention. FIG. 2 is an enlarged view of the piston assembly and connecting rod of FIG. 1. FIG. 3 is a cross-sectional view in the BB direction of FIG. 2. FIG. 3 is a view of the piston assembly of FIG. 2 as viewed from the CC direction. It is the figure which looked at FIG. 1 from the AA direction. FIG. 3 is a diagram when FIG. 2 is viewed from the DD direction. It is an enlarged view of the piston pin of FIG. FIG. 8 is a view of the piston pin of FIG. 7 viewed from the CC direction of FIG. 2. It is a figure which shows the modification of FIG.

A piston assembly and a reciprocating compressor including the piston assembly according to an embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a longitudinal sectional view of a reciprocating compressor 1 according to this embodiment. The reciprocating compressor 1 is classified into a hermetic compressor called a reciprocating compressor or a piston compressor, for example, and is used as a constituent device of a refrigeration cycle (not shown) incorporated in a vending machine, for example. The refrigeration cycle includes a path through which a refrigerant as a working fluid of the compressor 1 circulates. For example, a carbon dioxide refrigerant that is a non-flammable natural refrigerant is used as the refrigerant.

The compressor 1 includes a hermetic container 2, and in the hermetic container 2, an electric motor 4, a piston assembly 10 to which driving force of the electric motor 4 is transmitted via a crankshaft 6 and a connecting rod 8, and a piston assembly 10 Is accommodated in a cylinder block 12 into which the cylinder block 12 is slidably fitted.
The electric motor 4 includes a stator 14 that generates a magnetic field by power feeding and a rotor 16 that rotates by the magnetic field generated by the stator 14. Electric power is supplied to the stator 14 from the outside of the compressor 1 through an electrical component (not shown) fixed to the sealed container 2. Further, the rotor 16 is disposed coaxially inside the stator 14 and is shrink-fitted and fixed to the main shaft portion 18 of the crankshaft 6.

The crankshaft 6 is formed to have a main shaft portion 18 and an eccentric shaft portion 20 that is eccentric from the axial direction of the main shaft portion 18, and the main shaft portion 18 is rotatably supported by a frame 22 fixed in the sealed container 2. Has been. Further, the crankshaft 6 is arranged so as to intersect so that its axial direction is substantially perpendicular to the sliding direction of the piston assembly 10.
2 and 3, the connecting rod 8 is formed to have a large end (one end) 24 and a small end (other end) 26 at both ends. 24 is connected to the eccentric shaft portion 20, and the small end portion 26 is connected to a piston pin 28 constituting the piston assembly 10.

As shown in FIG. 1, the cylinder block 12 is formed with a cylinder bore 30 in which the piston assembly 10 is slidably fitted, and the cylinder block 12 of this embodiment is integrated with the frame 22. Is formed. In addition, a gasket 32, a valve plate 34, a gasket 36, and a cylinder head 38 are fastened to the cylinder block 12 by bolts 39 so as to close an opening opposite to the insertion side of the piston assembly 10 with respect to the cylinder bore 30.

As shown in FIG. 5, a suction hole and a discharge hole (not shown) for the refrigerant are formed in the valve plate 34, and the suction hole and the discharge hole are opened and closed by a plate-like suction valve 40 and a discharge valve 42.
The cylinder head 38 is formed with a suction chamber and a discharge chamber (not shown) for the refrigerant. The suction chamber communicates with the cylinder bore 30 through the suction hole when the suction valve 40 is opened in the suction stroke of the piston assembly 10, while the discharge chamber 42 is opened in the compression stroke of the piston assembly 10. Thus, the cylinder bore 30 communicates with the discharge hole.

When the crankshaft 6 is rotated by the electric motor 4, the connecting rod 8 swings in conjunction with the eccentric rotation of the eccentric shaft portion 20 with the piston pin 28 as a fulcrum, and interlocks with the swinging motion of the connecting rod 8. Then, the piston assembly 10 reciprocates in the cylinder bore 30. As described above, the reciprocating motion of the piston assembly 10 causes the refrigerant to be sucked into the cylinder bore 30 from the refrigeration cycle, the refrigerant is compressed in the cylinder bore 30 and discharged to the refrigeration cycle, and the series of processes is repeated.

Here, as shown in FIG. 2, the piston assembly 10 includes a piston 44, a piston pin hole 46, the above-described piston pin 28, fixing pin 48, piston side fixing pin hole 50, piston pin side fixing pin hole 52, and the like. It is composed of
The piston 44 has a head portion 54 and a skirt portion 58 that forms a hollow portion 56 that is open on the opposite side of the head portion 54. Further, the piston pin hole 46 is formed in the radial direction of the piston 44 so as to penetrate the side wall 60 facing the skirt portion 58 with the hollow portion 56 therebetween.

The piston pin 28 is formed in a cylindrical shape and is inserted through the piston pin hole 46. The fixing pin 48 is formed in a cylindrical shape. Then, by inserting the fixing pin 48 into the piston side fixing pin hole 50 and the piston pin side fixing pin hole 52, the piston pin 28 is fixed to the skirt portion 58, and a measure for preventing the piston 44 from coming off is applied.

As shown in detail in FIG. 4, the piston-side fixing pin hole 50 is formed in the piston pin hole from the end face 62 of the skirt portion 58 toward the extending direction of the skirt portion 58, that is, the sliding direction of the piston 44 with respect to the cylinder bore 30. It penetrates to 46. On the other hand, the piston pin side fixing pin hole 52 is formed so as to penetrate the piston pin 28 in the radial direction.
In the case of this embodiment, the piston-side fixing pin hole 50 has a larger diameter than the fixing pin 48, while the piston pin-side fixing pin hole 52 has a smaller diameter than the fixing pin 48. Accordingly, the fixing pin 48 inserted into the piston-side fixing pin hole 50 is pressed into the piston-side fixing pin hole 52 by press-fitting the fixing pin 48 inserted into the piston-side fixing pin hole 50 with a predetermined press-fitting jig. It is press-fitted and fixed in the side fixing pin hole 52, and a measure for preventing the piston pin 28 from coming off from the piston 44 is taken.

Further, the cylinder block 12 of this embodiment exposes the end face 64 of the piston pin 28 exposed from the piston pin hole 46 from the cylinder bore 30 at least when the piston assembly 10 is at the bottom dead center position as shown in FIG. It is formed with a notch 66 for making it.
6 to 8, the piston pin 28 of the present embodiment is formed to have a long groove (hole direction indicating portion, rotation adjusting portion) 68 on the end face 64. As shown in FIG. .

The long groove 68 extends substantially parallel to the hole direction of the piston pin side fixing pin hole 52 over almost the entire radial direction of the end face 64 and fits a jig such as a minus driver. It has a depth D, a groove width W, and a groove length L that can be combined. Therefore, the direction of the piston pin side fixing pin hole 52 can be easily adjusted using a minus driver or the like.

As shown in FIGS. 7 and 8, the end face 64 of this embodiment is formed in an arc shape along the inner wall of the cylinder bore 30.
Hereinafter, an assembly procedure of the piston crank mechanism of the compressor 1 of the present embodiment will be schematically described.
First, the eccentric shaft portion 20 is moved to the bottom dead center position by rotating the crankshaft 6.

Next, the large end 24 of the connecting rod 8 is inserted into and connected to the eccentric shaft portion 20 of the crankshaft 6 while the small end portion 26 of the connecting rod 8 is passed through the notch 66 of the cylinder block 12. In the case of the present embodiment, due to the structure in which the frame 22 and the cylinder block 12 are integrally formed, if the small end portion 26 is first connected to the piston pin 28, the large end portion 24 is moved to the eccentric shaft. It is impossible to connect to the part 20.

Next, the small end portion 26 is inserted into the hollow portion 56 of the piston 44.
Next, the connecting hole of the small end portion 26 and the piston pin hole 46 are aligned with a predetermined positioning jig. In this state, the piston pin 28 is inserted into the piston pin hole 46, and the small end portion 26 is inserted into the piston pin 28. Link.

Next, the fixing pin 48 is inserted into the piston-side fixing pin hole 50 from the end face 62 of the skirt portion 58. Since the piston-side fixing pin hole 50 has a larger diameter than the fixing pin 48, the fixing pin 48 can be inserted into the piston pin 28 through the piston-side fixing pin hole 50 without difficulty.
Here, depending on the insertion state of the piston pin 28 with respect to the piston pin hole 46, the piston side fixing pin hole 50 and the piston pin side fixing pin hole 52 may be displaced and not in a consistent state.

At this time, a jig such as a minus driver (not shown) is fitted into the long groove 68 formed in the end face 64 of the piston pin 28, and the piston pin 28 is rotated by rotating the jig in this state, thereby the long groove. The groove length direction of 68 is made to coincide with the extending direction of the skirt portion 58 from the end face 62 of the skirt portion 58, that is, the sliding direction of the piston 44 with respect to the cylinder bore 30. Accordingly, the opening on the piston side fixing pin hole 50 side of the piston pin side fixing pin hole 52 is matched with the opening of the piston side fixing pin hole 50 on the piston pin side fixing pin hole 52 side.

Next, in the piston-side fixing pin hole 50 and the piston-pin-side fixing pin hole 52 that are in a consistent state, the fixing pin 48 inserted into the piston-side fixing pin hole 50 is moved to the piston-pin-side fixing pin hole 52 by the aforementioned press-fitting jig. Thus, the fixing pin 48 inserted into the piston-side fixing pin hole 50 is press-fitted and fixed into the piston-pin-side fixing pin hole 52, whereby the piston pin 28 is prevented from coming off from the piston 44.

The operation of inserting the piston pin 28 into the piston pin hole 46 and the operation of press-fitting the fixing pin 48 into the piston-side fixing pin hole 50 and the piston-pin-side fixing pin hole 52 include a notch 66 formed in the cylinder block 12. As a result, the end face 64 is exposed from the cylinder bore 30 when the piston assembly 10 is at the bottom dead center position, and work can be performed without difficulty.

According to the piston assembly 10 and the compressor 1 of the present embodiment described above, the end pin 64 has the long groove 68, so that the piston pin 28 is inserted into the piston pin hole 46 and the piston pin side fixed pin hole 52 and the piston side. When the fixed pin hole 50 is displaced, the direction of the piston pin side fixed pin hole 52 formed in the piston pin 28 can be confirmed.
In addition, by fitting a jig into the long groove 68 and rotating the piston pin 28 using a flat-blade screwdriver or the like, the piston pin-side fixed pin hole 52 is easily aligned with the piston-side fixed pin hole 50. It can be. Therefore, the assemblability of the piston assembly 10 and the compressor 1 can be greatly improved.

In addition, since the frame 22 and the cylinder block 12 are integrally formed, it is not necessary to fasten the cylinder block 12 to the frame 22 with bolts, so that it is not necessary to secure the wall thickness of the fastened portion in the cylinder block 12. Therefore, since the weight of the bolt and the fastening margin can be reduced, and the volume of the fastening margin of the cylinder block 12 can be reduced, the weight of the piston assembly 10 and the compressor 1 can be further reduced. Miniaturization can be realized.

Further, by providing the cylinder block 12 with the notch portion 66, the rotation adjustment for rotating and positioning the piston pin 28 so that the piston pin side fixing pin hole 52 matches the piston side fixing pin hole 50 described above. Even if the frame 22 and the cylinder block 12 are integrally formed as in the present embodiment, it can be easily performed on the exposed end face 64. Therefore, the further assembly of the piston assembly 10 and the compressor 1 can be improved.

Further, even if the end face 64 is formed in an arc shape along the inner wall of the cylinder bore 30 to form the long groove 68 in the end face 64 and the end face 64 is exposed from the piston pin hole 46, the inner wall of the cylinder bore 30 is also formed. While preventing the end face 64 from interfering with the piston 44, the outer diameter of the piston 44 can be made as small as possible, and the length of the piston pin 28 can be made as long as possible. Accordingly, the piston assembly 10 and the compressor 1 can be further reduced in weight and size without being restricted by the formation of the long groove 68.

The present invention is not limited to the piston assembly 10 and the compressor 1 of the above embodiment, and various modifications are possible.
For example, in the above-described embodiment, by providing the long groove 68 on the end face 64 of the piston pin 28 exposed from the piston pin hole 46, the hole direction indicating portion that clearly indicates the hole direction of the piston pin-side fixing pin hole 52 is provided in the long groove 68. Then, based on this hole direction clearly indicating portion, the piston pin 28 is rotated so that the piston pin side fixing pin hole 52 is aligned with the piston side fixing pin hole 50, and the rotation adjustment is performed for positioning using a minus driver or the like. Both functions can be provided.

As a result, the two functions essential for improving the assemblability of the piston assembly 10 and the compressor 1 can be provided by the simple-shaped portion of the single long groove 68. Therefore, the piston assembly 10, and thus the compressor The processability of No. 1 is improved and suitable. However, the present invention is not limited to this as long as it has the hole direction indication part and the rotation adjustment part described above.

Specifically, as shown in FIG. 9, a cross-shaped groove where a long groove 70 a parallel to the piston pin-side fixing pin hole 52 and a short groove 70 b orthogonal to the piston pin-side fixing pin hole 52 intersect on the end face 64. 70 may be formed. In this case, the cross-shaped groove 70 has a function as a hole direction indicating portion. At the same time, the piston pin 28 can be rotated by fitting and turning a jig such as a plus driver that is easier to fit and position the cross-shaped groove 70 than a minus driver and is easy to use. The cross-shaped groove 70 can easily have a function as a rotation adjusting portion. It is also possible to use a special tool other than a minus driver or a plus driver.

Further, two recesses spaced apart in parallel to the piston pin side fixing pin hole 52 may be provided on the end face 64. In this case, an imaginary line connecting the two recessed portions separated from each other functions as a hole direction clearly indicating portion, and further, in a state where the tip of the fixing jig is fitted and fixed to one recessed portion, the other recessed portion is rotated. The piston pin can be turned by fitting the tip of the jig and turning the turning jig around the fixed jig, so that it can function as a turning adjusting portion.

In the above-described embodiment, the reciprocating compressor 1 provided with the piston assembly 10 has been described. However, the present invention is not limited to this, and the piston assembly 10 alone may be used. Of course, the present invention can be applied to a compressor other than the reciprocating compressor 1 and a piston crank device.

DESCRIPTION OF SYMBOLS 1 Reciprocating compressor 6 Crankshaft 8 Connecting rod 10 Piston assembly 12 Cylinder block 18 Main shaft part 20 Eccentric shaft part 22 Frame 24 Large end part (one end part)
26 Small end (other end)
28 Piston pin 30 Cylinder bore 44 Piston 46 Piston pin hole 48 Fixed pin 50 Piston side fixed pin hole 52 Piston pin side fixed pin hole 56 Hollow part 58 Skirt part 62 End face of skirt part 64 End face of piston pin 66 Notch part 68 Long groove ( Hole direction indication part, rotation adjustment part)

Claims

A piston having a skirt part forming a hollow part;
A piston pin hole penetrating through the skirt,
A piston pin inserted through the piston pin hole;
A fixing pin for fixing the piston pin to the skirt portion;
A piston-side fixing pin hole that is penetrated from the end face of the skirt portion to the piston pin hole, and through which the fixing pin is inserted;
A piston pin-side fixing pin hole formed in the piston pin, into which the fixing pin inserted into the piston-side fixing pin hole is inserted;
The piston pin includes, on the end surface exposed from the piston pin hole, a hole direction indicating portion that clearly indicates a hole direction of the piston pin side fixing pin hole, and the piston pin side fixing pin based on the hole direction specifying portion. A piston assembly, comprising: a rotation adjusting portion for rotating and positioning the piston pin so as to match the hole with the piston-side fixing pin hole.
2. The piston according to claim 1, wherein the piston pin has a long groove parallel to a hole direction of the piston pin side fixed pin hole as the hole direction clearly defining portion and the rotation adjusting portion on the end surface thereof. assembly.
A piston assembly according to claim 1 or 2,
A crankshaft having a main shaft portion and an eccentric shaft portion;
A frame that rotatably supports the main shaft portion;
A connecting rod having one end connected to the eccentric shaft and the other end connected to the piston pin;
A cylinder block having a cylinder bore into which the piston assembly is slidably fitted;
The reciprocating compressor characterized in that the axial direction of the crankshaft and the sliding direction of the piston assembly intersect, and the frame and the cylinder block are formed integrally.
4. The reciprocating compressor according to claim 3, wherein the cylinder block has a notch for exposing the end face of the piston pin from the cylinder bore when the piston assembly is at a bottom dead center position.
The reciprocating compressor according to claim 3 or 4, wherein the end face of the piston pin has an arc shape along an inner wall of the cylinder bore.