JP4569499B2 - Compressor - Google Patents

Description

  The present invention relates to a compressor which is mounted on a refrigeration apparatus such as a refrigerator and performs a cooling operation by compressing and discharging a refrigerant.

  In compressors exported to North America and Europe, it is obliged to attach an earth terminal with three or more threads on the outer shell of the compressor according to the global safety standards. Conventionally, in order to secure this thread, a flat earth terminal tapped with a thick iron plate with a thickness of 2 mm or more has been used, and paint coating due to the outer shell coating of the compressor has been prevented. In order to achieve this, there is known one covered with a rubber-made ground cap having a uniform thickness (see, for example, Patent Document 1).

  The conventional compressor will be described below with reference to the drawings.

  8 is an external view of a conventional compressor, FIG. 9A is an enlarged cross-sectional view of a main part, and FIG. 9B is an enlarged view of the main part.

  8 and 9, a bracket 2 formed of an iron plate having a thickness of 2 mm is fixed to the outer surface of the sealed container 1 by welding. The earth terminal 3 is integrally formed by bending outward from the side surface of the bracket 2 and is formed as a plane having a plate thickness of 2 mm.

  An M4 screw portion 4 is formed on the flat portion of the earth terminal 3 by tapping.

  The earth cap 5 is a rubber cap, and is provided with an elongated hole 6 that is deep and straight in the depth direction, and the entire surface is formed with a uniform thickness. The opening width of the long hole 6 is smaller than the thickness and width of the earth terminal 3, and the depth dimension is substantially equal to the plane length of the earth terminal 3.

  The earth cap 5 is inserted while being press-fitted into the flat portion of the ground terminal 3, covers the ground terminal 3 in a tightening manner, and seals the entire flat portion of the ground terminal 3.

  The operation of the above configuration will be described below.

  After all the components are assembled, the compressor is coated with an outer shell for the purpose of preventing rust. If paint adheres to the earth terminal 3, electrical conduction is hindered and the earth function is hindered, so that the outer shell coating is performed while the earth terminal 3 is covered with the earth cap 5.

  The outer shell coating method is generally a method in which the entire compressor is dipped in a liquid paint stored in a tank (not shown) and then dried. If there is a slight gap, the liquid paint will infiltrate. Since the earth cap 5 is sealed in a state of being press-fitted into the earth terminal 3, the paint is prevented from adhering to the flat surface portion and the screw portion 4 of the earth terminal 3.

  When the compressor completed through these processes is mounted on a system such as a refrigerator or a freezer, the earth cap 5 is removed.

Then, a ground wire (not shown) on the system side is connected to the earth terminal 3 and connected and fixed through a predetermined screw (not shown) that is tightened to the screw portion 4 to complete the ground connection.
JP-A-6-257567

  However, in the above-described conventional configuration, even if the material is reduced by reducing the thickness of the earth terminal and the weight is reduced, the minimum board thickness required for providing three or more threads on the earth terminal is It was inevitably determined, and it was difficult to make the earth terminal thinner than the minimum thickness.

  Also, if the ground terminal is covered with a grounding cap and the grounding terminal is covered with a grounding cap that is thicker than the threaded part of the grounding terminal and has three or more threads secured, There was a problem that the paint penetrated and the paint adhered to the screw portion of the earth terminal.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and provides a compressor with high productivity while realizing weight reduction by making the ground terminal thin and reliably preventing the paint from entering the screw portion. With the goal.

  In order to solve the above-mentioned problems, the compressor of the present invention is a rubber in which the wall thickness of the opening is thicker than the wall thickness of the cavity, and the inner width of the cavity is smaller than the thickness of the screw portion of the earth terminal. It consists of a cap made of cap, and by simply inserting and covering the ground cap, the thin part of the ground terminal is tightened and sealed on the inner plane of the opening, and the compact part of the ground terminal is sandwiched between the inner plane of the cavity Since the sealing in two stages of sealing is possible, in the earth terminal that has been made thin, it is possible to more reliably prevent the paint from entering the threaded portion of the earth terminal.

  Since the compressor of the present invention can more reliably prevent the paint from entering the screw portion of the ground terminal, the weight of the ground terminal can be reduced and the paint can be prevented from adhering to the screw portion. Therefore, an effect that a highly productive compressor can be provided is obtained.

  The invention according to claim 1 of the present invention has an earth terminal fixed to the outer surface of the sealed container and having a thickened screw part, and a rubber earth cap fitted into the earth terminal before painting, The earth cap is provided with an opening at one end and a cavity for accommodating at least the screw part, the wall thickness of the opening is thicker than the wall thickness of the cavity, and the inner width of the cavity is set to the screw part of the earth terminal. It can be made lighter by thinning the earth terminal, and by simply inserting and covering the earth cap, the thin part of the earth terminal can be tightened and sealed on the inner plane of the opening, Since it is possible to seal in two stages by sandwiching the sealed part of the earth terminal with the inner plane of the cavity and sealing it, it prevents the paint from entering the screw part of the earth terminal Rukoto can, it is possible to provide a highly productive compressor.

  The invention according to claim 2 is the invention according to claim 1, wherein the wall thickness of the cavity is further reduced to 0.7 times or less of the wall thickness of the opening. Since the seal in the opening portion and the seal in the hollow portion can be effectively made compatible by the optimum balance, the infiltration of the paint into the screw portion of the ground terminal can be more reliably prevented.

  The invention according to claim 3 is the invention according to claim 2, wherein the inner width of the hollow portion is further reduced to 0.9 times or less of the thickness of the screw portion. By optimizing the pinch allowance, even if the seal of the opening is insufficient, the seal of the cavity can be reliably secured, so that the penetration of paint into the screw part of the earth terminal can be prevented more reliably be able to.

  The invention described in claim 4 is the same as that described in claim 2, except that the step size between the inner width of the opening and the inner width of the cavity is smaller than the inner width of the opening. In the process, when removing from the mold after molding, it is possible to prevent tearing of the opening due to stretching the opening to the inner width of the cavity, so that a highly productive compressor can be provided. .

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the earth cap is formed of an NBR material, and there is no concern about corrosion of the metal, and low cost is realized. can do.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments.

(Embodiment 1)
1 (a) and 1 (b) are external views of a compressor according to Embodiment 1 of the present invention, FIG. 2 (a) is an enlarged sectional view of an earth terminal according to the same embodiment, and FIG. 2 (b) is the same embodiment. 3 (a) and 3 (b) are detailed assembly drawings in the embodiment, FIG. 4 (a) is a detailed sectional view of the earth cap in the embodiment, and FIG. 4 (b) is the same in the embodiment. 5 is a detailed diagram of the earth cap in the embodiment, FIG. 5 is a diagram showing an experimental result showing the correlation between the ratio of the wall thickness of the cavity to the wall thickness of the opening in the same embodiment and the sealing performance in the opening, and FIG. The figure which shows the experimental result which shows the correlation with the ratio of the internal width of the cavity part with respect to the thickness of the screw part in the same embodiment, and sealing performance, FIG. 7 is the inside width of the opening part and the inside of the cavity part in the same embodiment. Step size of width and opening when molding earth cap It shows an experiment result showing a correlation tearing.

  1 to 4, a bracket 101 is welded and fixed to the outer surface of a hermetic container 100 that forms the outer shell of the compressor. The bracket 101 is formed by bending an iron plate having a thickness of 1.4 mm, and an electrical component cover (not shown) is fixed. An earth terminal 102 is formed integrally with the bracket 101, and the earth terminal 102 is fixed to the outer surface of the hermetic container 100 together with the bracket 101.

  As with the bracket 101, the ground terminal 102 has a plate thickness of 1.4 mm and a lateral width of 8 mm. The flat portion is thickened into a convex shape by burring, and the inner diameter portion is tapped with M4 to form a screw portion 103.

  The thickness 104 of the screw portion 103 is molded to 3.5 mm, so that the screw portion 103 secures three or more threads even in consideration of flat sagging caused by burring.

  The earth cap 105 covers the vicinity of the screw portion 103 of the earth terminal 102.

  The earth cap 105 is a rubber cap made of NBR material, and has an opening 106 at one end and a cavity 107 inside. The inner width 111 of the opening is 0.2 mm with respect to the plate thickness and width of the earth terminal 102. A fastening margin is provided, and the width in the plate thickness direction is 1.2 mm and the lateral width is 7.8 mm.

  The wall thickness 109 of the cavity is 1.5 mm, which is 0.6 times thinner than the 2.4 mm of the wall thickness 108 of the opening. This is because when the screw portion 103 is sandwiched, the inner wall of the cavity portion 107 is pushed and deformed, but if the wall thickness 109 of the cavity portion is thick, the deformation cannot be absorbed and the inner wall 111 of the opening portion is pushed and expanded. This is to prevent the seal of the opening 106 from becoming unstable.

  FIG. 5 shows the experimental results showing the correlation between the ratio of the wall thickness 108 of the opening to the wall thickness 109 of the cavity and the sealing performance at the opening 106. This is a case where the ratio of the wall thickness 109 of the cavity to the wall thickness 108 of the opening is used as a parameter, and the range from 0.5 times to 1 time is distributed every 0.1 times and immersed in the liquid paint. The sealing performance of the opening 106 is evaluated. The number of experiments was 10 times for each parameter. If the sealing property was good, the result was ○, and the case where the liquid paint penetrated from the opening 106 was marked as “poor”.

  From this experimental result, it can be seen that when the ratio of the wall thickness 108 of the opening to the wall thickness 109 of the cavity is 0.8 times or more, a liquid paint enters from the opening 106. It can be seen that the ratio of the wall thickness 109 of the cavity to the wall thickness 108 of the opening is optimally 0.7 times or less in order to realize the two-stage seal of the present invention.

  The inner width 110 of the cavity is 3 mm, which is 0.85 times smaller than 3.5 mm of the thickness 104 of the screw portion. This is because the screw portion 103 is securely sandwiched and sealed by the inner wall of the cavity portion 107.

  FIG. 6 shows the experimental results showing the correlation between the ratio of the inner width 110 of the hollow portion to the thickness 104 of the screw portion and the sealing performance. This is based on the ratio of the inner width 110 of the cavity to the thickness 104 of the thread as a parameter, and is distributed every 0.1 times from 0.5 times to 1 time, and the cavity 107 when immersed in a liquid paint The sealing performance was evaluated. The number of experiments was 10 times for each parameter, and “◯” if the sealing property was good, and “X” if the liquid paint entered from the cavity 107 was problematic.

  From this experimental result, it can be seen that when the ratio of the inner width 110 of the hollow portion to the thickness 104 of the screw portion is 1 or more, the liquid paint enters from the hollow portion 107. In order to ensure the sealing of the cavity 107 according to the present invention, it can be seen that the ratio of the inner width 110 of the cavity to the thickness 104 of the thread must be 0.9 times or less.

  The step size of the inner width 111 of the opening and the inner width 110 of the cavity is 0.9 mm, which is smaller than 1.2 mm of the inner width 111 of the opening. This is to prevent tearing of the opening 106 due to extending the inner width 111 of the opening to the inner width 110 of the cavity when the earth cap 105 is removed from the mold after molding in the manufacturing process of the earth cap 105. .

  FIG. 7 shows the experimental results showing the correlation between the step size of the inner width 111 of the opening and the inner width 110 of the cavity and the tearing of the opening 106 when the earth cap 105 is molded. This is because the step size between the inner width 111 of the opening and the inner width 110 of the cavity is changed to a parameter every 0.1 mm from 0.5 mm to 1.5 mm, and the opening 106 is removed from the mold after molding. This is an evaluation of the presence or absence of tearing. The number of experiments was 10 times for each parameter, and “O” was given if no tearing occurred, and “X” was given if tearing occurred.

  From this experimental result, when the step size between the inner width 111 of the opening and the inner width 110 of the cavity is 1.3 mm or more exceeding the inner width 111 of the opening, the opening is removed when the mold is removed from the mold after molding. It can be seen that 106 tears come out. In order to reliably prevent the opening 106 of the present invention from tearing, it is understood that the step size between the inner width 111 of the opening and the inner width 110 of the cavity must be equal to or smaller than the inner width 111 of the opening.

  About the compressor comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  In the manufacturing process of the compressor, an operation of covering the earth terminal 102 with the earth cap 105 is performed before entering the outer shell painting process. Since the ground terminal 102 has a thickened screw portion 103 in the flat surface portion, the opening 106 of the ground cap 105 is greatly stretched by the screw portion 103 and passes through the flat surface portion to complete the insertion. At this stage, the opening portion 106 of the earth cap 105 tightens and seals the flat portion of the earth terminal 102, and the cavity portion 107 is sealed with the screw portion 103 interposed therebetween.

  Next, outer shell coating is performed for the purpose of rust prevention of the compressor. In the outer shell coating process, the entire compressor is immersed in the liquid paint collected. At this time, the liquid paint is prevented from entering the screw portion 103 by the two-stage seal of the tightening seal in the opening 106 of the earth cap 105 and the sandwiching seal in the cavity 107.

  Here, even if the sealing performance of the opening portion 106 is lowered due to a problem such as the entry of a foreign substance into the sealing portion of the opening portion 106 or the deformation of the sealing portion and the paint enters, the screw portion 103 is brought into contact with the screw portion 103 by the pinching seal of the cavity portion 107. Can prevent the ingress of paint. On the other hand, even if there is a problem with the sandwiching seal of the cavity 107, the seal of the opening 106 can normally prevent the paint from entering the screw portion 103. Therefore, according to this embodiment, since the two-stage sealing function is formed, the probability that the paint enters the screw portion 103 is extremely low, and a high-quality compressor can be provided.

  When the compressor completed through these processes is mounted on a system such as a refrigerator or a refrigeration apparatus, the ground cap 105 is removed, and a ground wire (not shown) on the system side is fastened to a screw portion 103 (see FIG. (Not shown) is connected and fixed to the earth terminal 102, and the earth connection is completed.

  As described above, according to the present embodiment, as is clear from the experimental results of FIG. 5, the ratio of the wall thickness of the cavity to the wall thickness of the opening is 0.7 times or less, By simply inserting the earth cap and covering it, the thin part of the ground terminal is tightened and sealed on the inner plane of the opening, and the compact part of the ground terminal is sandwiched and sealed on the inner plane of the cavity. Can be made effective.

  In addition, as is clear from the experimental results of FIG. 6, by setting the ratio of the inner width of the hollow portion to the thickness of the screw portion to 0.9 times or less, even if the sealing of the opening portion is insufficient, The seal of the cavity can be ensured reliably.

  Furthermore, as is clear from the experimental results of FIG. 7, by making the step size between the inner width of the opening and the inner width of the cavity equal to or less than the inner width of the opening, in the earth cap manufacturing process, When removing from the mold, it is possible to prevent tearing of the opening due to stretching the opening to the inner width of the cavity.

  Therefore, according to the present embodiment, it is possible to provide a highly productive compressor while realizing cost reduction by reducing the thickness of the ground terminal and reliably preventing the paint from entering the screw portion. is there.

  Here, in the present embodiment, the earth terminal 102 is formed integrally with the bracket 101, and only the screw portion 103 can be thickened by burring, so that not only the earth terminal 102 but also the area of the material is reduced. The entire large bracket 101 can be thinned, and the cost reduction effect due to the weight reduction of the material is very large.

  In the present embodiment, the earth terminal 102 is illustrated as being integrally formed with the bracket 101, but the earth terminal 102 may be formed alone and directly welded and fixed to the outer surface of the sealed container 100. Needless to say, similar effects can be obtained.

  As described above, the hermetic electric compressor according to the present invention enables an inexpensive compressor that does not enter the screw portion of the earth terminal while ensuring high productivity. First, it can be applied to a compressor used in a refrigeration cycle such as a vending machine, a refrigeration showcase, a dehumidifier.

(A) External view of compressor in embodiment 1 of the present invention (b) External view of compressor in the embodiment (A) Ground terminal enlarged sectional view in the same embodiment (b) Ground terminal enlarged view in the same embodiment (A) Detailed assembly diagram in the same embodiment (b) Detailed assembly diagram in the same embodiment (A) Detailed cross-sectional view of the ground cap in the same embodiment (b) Detailed view of the ground cap in the same embodiment The figure which shows the experimental result which shows the correlation with the ratio of the wall thickness of the cavity part with respect to the wall thickness of the opening part in the same embodiment, and sealing performance The figure which shows the experimental result which shows the correlation with the ratio of the inner width of the cavity part with respect to the thickness of the screw part in the same embodiment, and sealing performance The figure which shows the experimental result which shows the correlation of the level | step difference dimension of the inner width of the opening part in the same embodiment, the inner width of a cavity part, and the tearing of the opening part at the time of earth cap molding External view of conventional compressor (A) Main part enlarged sectional view of a conventional compressor (b) Main part enlarged view of a conventional compressor

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Airtight container 102 Ground terminal 103 Screw part 104 Thickness of screw part 105 Ground cap 106 Opening part 107 Cavity part 108 Wall thickness of opening part 109 Wall thickness of cavity part 110 Inner width of cavity part 111 Inner width of opening part

Claims (5)

  A ground terminal fixed on the outer surface of the sealed container and having a thickened screw portion, and a rubber ground cap fitted to the ground terminal before painting, the ground cap having an opening at one end A cavity portion for accommodating at least the screw portion; a wall thickness of the opening portion is made thicker than a wall thickness of the cavity portion; and an inner width of the cavity portion is made smaller than a thickness of the screw portion of the earth terminal. Compressor.   The compressor according to claim 1, wherein the wall thickness of the hollow portion is 0.7 times or less the wall thickness of the opening.   The compressor according to claim 2, wherein an inner width of the hollow portion is 0.9 times or less of a thickness of the screw portion.   The compressor according to claim 2, wherein the step size between the inner width of the opening and the inner width of the cavity is smaller than the inner width of the opening.   The compressor according to any one of claims 1 to 4, wherein the earth cap is formed of an NBR material.

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