JPH0458081A - Piston device for compressor - Google Patents

Abstract

PURPOSE:To avoid sliding wear and a scuffing phenomenon by forming sintered material in which powdery metal is heated in such a way as to be sintered while being dispersed so as to be bonded, in the inner diametric surfaces of a cylindrical layer and a cylindrical small end section, and thereby almost freely regulating the blending of iron powder which is raw material for powdery metallurgy, and other various metals and constituents in response to the output of a compressor and environment in service. CONSTITUTION:Power is transmitted while rotating motion by a motor is converted into reciprocal motion through a piston mechanism, and a device is concurrently equipped with a connecting member 1 which is made up out of a cylindrical large end section 2 engaged with the rotating shaft of the motor at one end, a cylindrical small end section 3 engaged with the pin of a piston at the other end, and of a connecting rod (rod section) connecting these end sections 2 and 3 to each other. In this case, the inner diametric surfaces of the cylindrical large and small sections 2 and 3 of the connecting member 1 are formed with sintered material 5 and 6 in which powdery metal is heated so as to be sintered while being dispersed so as to be bonded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method of configuring a rod (connecting member) of a reciprocating compressor using a connecting rod type compression mechanism, and particularly relates to a method for configuring a rod (connecting member) at a large end and a small end of the rod. The present invention relates to a method of configuring a rod that allows easy selection of a metal material according to the sliding characteristics of the inner wall of the section and that is suitable for firmly joining a power transmission strength member.

[Conventional technology]

In the past, there have been many examples in which a known connecting rod type compression mechanism has been adopted, as shown in Japanese Utility Model Application No. 52-8912. Therefore, these adoption examples will be explained in detail below using FIGS. 5 to 7.

FIG. 5 shows an example of the structure of a small-sized refrigeration compressor used for refrigerators and the like. 11 is a closed container, 1
2 is the compressor main body, 13 is the frame, 14 is the rotating shaft, 15
is the cylinder, 16 is the piston, 17 is the piston pin, 1
8 is a rod, 19 is an electric motor, 20 is a stator, and 21 is a rotor.

That is, the compressor main body 12 is assembled with the frame 13 as the core, and the rotating shaft 14 is inserted through the bearing 13a machined in the frame 13, and then the large end of the rod 18 is attached to the eccentric portion 14a of the rotating shaft 14. 18a is fitted.

The small end 18b of the rod 18 is connected to a piston 16 inserted into a bore 15a of a cylinder 15 that is separate from the frame 13.
Fits with the piston pin 17 inserted into the side hole 16a of the
The rotational motion of the eccentric portion 14a of the rotating shaft 14 is controlled by the piston 16.
It exhibits the function of converting it into reciprocating motion.

The electric motor 19 is composed of a stator 20 and a rotor 21, and the lower part 14b of the rotating shaft 14 that constitutes the compressor main body 12 mentioned above.
Then, the inner diameter 21a of the rotor 21 is joined by press fitting or shrink fitting. Furthermore, the rotor 2I and the stator 20 are fixed to the frame 13 with bolts or the like with an appropriate gap provided therebetween.

In this state, the compressor is housed in the closed container 11, and by energizing the electric motor 19 through the closed container 11, rotational force is applied to the rotating shaft 14, and the desired compressor function is exerted.

The rod 18 used in this conventionally known compressor converts the rotational movement of the rotating shaft 14 into the reciprocating movement of the piston 16.
Generally, the configuration is as shown in FIG. 6 or 7.

That is, in the rod 18 shown in FIG. 6, the large end 18a1, the small end 18b, and the connecting part 18c are integrally formed by forging or the like. However, depending on the specifications of the compressor, such as the magnitude of the compression force and the operating atmosphere, the large end 18a and the small end 18 that slide on the rotating shaft 14 and the piston pin 17.
b needs to be an appropriate combination of materials, but in conventionally known integral rods, the rod and the sliding surface are made of the same material, which has the disadvantage that selection is limited. Therefore, various surface treatments and heat treatments are required as necessary, resulting in problems such as decreased machinability and finishing accuracy. FIG. 7 shows a structure that has been conventionally adopted as one way to overcome the drawbacks of the above-mentioned integral rod. That is, the large end 1 of the integral rod similar to FIG.
A prepared hole having an appropriate inner diameter is formed in each of the small end portions 18b of 8a1, and a ring-shaped bushing metal 18d is formed on the inner diameter of the pilot hole.
, 18e are press-fitted. However, although the method shown in FIG. 7 makes it possible to appropriately select the material of the metal, it has the disadvantage that it is unstable to ensure bonding strength depending on the press-fitting.

[Problem to be solved by the invention]

The above conventional technology has limitations in the range of selection of appropriate sliding surface materials and does not take into account the bonding strength of metal bushings, resulting in problems with compressor performance, part workability, and reliability. was there.

The present invention aims to eliminate these drawbacks of the prior art, and utilizes the characteristics of a strength member and a sliding member to create a rod component for a compressor, and in particular, freely selects the sliding member. The purpose is to provide a rod with a configuration that can be used.

In addition, compared to conventional structures that require full-scale machining, by dividing the components and applying precision forging technology or welding technology, the rod can be easily adapted to various model conversions at low cost. Our goal is to provide the following.

[Means to solve the problem]

The configuration of the piston device for a compressor of the present invention for solving the above problems is capable of converting rotational motion by a motor into reciprocating motion by a piston mechanism and transmitting power, and one end of the piston device is connected to the rotating shaft of the motor. In a piston device for a compressor, the connecting member has a cylindrical large end that fits, the other end has a cylindrical small end that fits with a pin of the piston, and a connecting rod that connects these. The inner diameter surfaces of each of the cylindrical large end and small end of the connecting member are provided with a sintered material made by heating and sintering powdered metal and diffusion bonding the same.

[Effect]

The rod outer shell, which is the strength member of the main structure of the present invention,
It is made of a material that is not directly related to the sliding characteristics and is made of a material such as forged, or the outer diameter of the large end and small end are made of a pipe material that is relatively low cost and has excellent weldability. The connecting rod parts are formed from round bars, etc., and after welding them together and integrating them, a powder metal sintering process is applied to the inner diameter surface of the hole opened at each of the large and small ends. By integrating the sintered material by diffusion bonding the inner diameter surface and the powdered metal, the sintered material made of powdered metal can be held firmly and reliably, and it also has a wide range of latitude in selecting the material for the sintered material. It can be configured as follows.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

Figure 1 shows the completed shape of the rod of the present invention.
2 is a rod (connecting member), 2 is a cylindrical large end, 3 is a cylindrical small end, 4 is a connecting rod, 5 is a large end metal, and 6 is a small end metal.

FIG. 2 is a perspective view showing the state of each component of the rod 1 shown in FIG. 1 before being joined together. That is, the large end portion 2 and the small end portion 3 are formed into a cylindrical shape by plastic working of an iron pipe or an iron plate.

Further, the connecting rod 4 is formed by cutting a round bar of an appropriate diameter into an appropriate length.

Furthermore, the large end metal 5 and the small end metal 6 are formed by molding powders of appropriate materials according to their intended use, and are press-formed. FIG. 3 shows a cross-sectional view of the large end 2, small end 3, and connecting rod 4 of the elements shown in FIG. 2, each of which is welded by electric resistance welding or the like.

By forming the large end 2, the small end 3, and the connecting rod 4 from the same type of steel and welding them together in this way, it is possible to achieve the desired structure with considerably high strength and under stable conditions.

Figure 4 shows the large end 2 of the strength member thus obtained.
This is a cross-sectional view showing a state in which metals 5 and 6 are inserted, the outer diameters of which are shaped to form an appropriate gap between the inner diameter of the small end portion 3 and the inner diameter of the small end portion 3. Here, it is preferable to select metals 5 and 6 that have the property of causing jI tensile deformation when heated to the sintering temperature.

In this state, the connecting member is inserted into a sintering furnace controlled at an appropriate temperature, and heated and sintered so that the large end 2, small end 3 and metals 5 and 6 expand and come into close contact with each other, and In addition to being able to be firmly held by diffusion bonding, the diffusion sintering of the metals 5 and 6 itself has been completed, and the rod (connecting member) l as shown in Figure 1 has been completed.
is completed.

According to this embodiment, the machining range can be significantly reduced compared to the conventional rod forming method in which the entire structure was made of cast material, etc., and the large end and small end Since the spacing can be freely met by changing only the length of the connecting rod, it has the advantage of being able to quickly respond to changes in the capacity of the compressor. In addition, with respect to the bonding strength, unlike the conventional structural structure in which separate bushings are press-fitted and the elastic tightening of mutual members is based on force, the bonding of the present invention is extremely strong due to atomic diffusion between the two metals. Since it can be formed uniformly and with high strength, there is no risk of problems such as loosening or pulling out during compressor operation.

When selecting metal materials, the characteristics of powder metallurgy are that various desired materials can be easily obtained by appropriately selecting powder metal raw materials according to the specifications of the sliding parts to be applied, and as a result, it can be used in a variety of environments. A wide variety of products can be accommodated.

〔Effect of the invention〕

Since the present invention is configured as described above, it has the following effects.

The composition of iron powder, which is the raw material for powder metallurgy, and various other metals and components can be adjusted almost freely according to the output of the compressor and the usage environment, making it possible to avoid the occurrence of sliding wear and jamming phenomena. There is no need for special surface treatment or hardening of conventional monolithic rods.

In addition, by simultaneously sintering the strength member and the metal intended for sliding resistance, it is possible to integrate them through diffusion bonding, which eliminates concerns about strength and improves reliability compared to conventional press-fitting. It will be done.

Furthermore, compared to materials such as castings or forgings, each component can be divided into simpler shapes and each component can be prepared, and the main strength members can be made from electrical resistance materials that are inexpensive in terms of equipment and easy to handle. Since it can be formed by welding, it is possible to reduce the necessary costs, and there is an advantage that the processing costs for each part and welding work are extremely small, and it is possible to change compressor specifications,
For example, if it is necessary to change the distance between the large end and small end due to upsizing or downsizing, this can be easily done by simply changing the length of the connecting rod. The practical effects are significant.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of the configuration of a compressor rod according to the present invention, FIG. 2 is a perspective view showing an example of each component of the rod shown in FIG. 1, and FIG. 3 is a perspective view of the rod shown in FIG. 1. 4 is a sectional view showing an example of the welded state of the strength member of the rod in FIG.
The figure is a longitudinal sectional view showing an example of a connecting rod type compressor, Fig. 6 is a perspective view showing an example of the integrally molded shape of a conventionally known rod, and Fig. 7 is an example of a conventionally known rod in which a separate metal is press-fitted. FIG. Explanation of symbols> 1...Rod (connecting member) 2...Big end 3...Small end 4...Connecting rod 5...Big end metal 6...Small end metal 14...Rotation axis
15... Cylinder 19... Electric motor 6 Small j crystal shell metal ff'J (2) De 4 Fig. 5 91 Koya'' 1 Metano L I 6 Fig. 1 Fig.

Claims (1)

[Claims] 1. Rotational motion by a motor can be converted into reciprocating motion by a piston mechanism to transmit power; one end is
A piston device for a compressor, comprising a connecting member consisting of a large cylindrical end that fits with a rotating shaft of a motor, a small cylindrical end that fits with a pin of a piston, and a connecting rod that connects these. A piston device for a compressor, characterized in that each of the cylindrical large end portion and the small cylindrical end portion is provided with a sintered material formed by heating and sintering powdered metal and diffusion bonding on the inner diameter surface thereof.