JPS589273B2 - horizontally opposed compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a horizontally opposed compressor that reciprocates a double-headed piston within a cylinder, and particularly relates to a horizontally opposed compressor that reciprocates a double-headed piston within a cylinder, and particularly relates to a horizontally opposed compressor that reciprocates a double-headed piston within a cylinder. Concerning surface lubrication.

As shown in FIGS. 1 and 2, the horizontally opposed compressor has a double-headed piston 3 that is slidably fitted on the inner wall of a cylinder 25.
The rotation of the drive shaft 1 that passes through the piston intermediate portion in a direction perpendicular to the piston axis causes the eccentric cam portion 10 of the drive shaft to rotate.
The suction gas is compressed and discharged by being reciprocated by a slider 4 mounted on the outer periphery of the compressor.

In such a horizontally opposed compressor, the sliding surfaces 16, 16 (see FIG. 5) of the slider 4 that reciprocates between the opposing planes 23, 23 between the piston heads and the opposing planes are as follows:
Because they slide against each other at high speed under rapidly fluctuating high contact pressure, it was necessary to provide sufficient lubrication to prevent wear during this time.

That is, if the sliding surfaces of the piston and the slider are not sufficiently lubricated, the sliding resistance and sliding surfaces will become abnormally worn, making it impossible to operate the compressor.

Conventionally, in order to lubricate the sliding surfaces between the piston and slider, for example, a trochoid pump was installed at one end of the drive shaft, and the pump sucked lubricating oil from an oil bun formed at the bottom of the compressor. Through a main oil passage bored in the shaft center and a branch passage connecting the outer periphery of the eccentric cam part and the main oil passage,
Furthermore, oil was forcibly supplied through a through hole that communicated the inner and outer circumferences of the slider.

According to this method, since the sliding surfaces of the piston and the slider are forcibly lubricated with oil using a pump, an oil van, an oil supply pump, and an oil passage are required, resulting in a complicated structure and increased weight.

In addition, in a horizontally opposed compressor for refrigerant compression, in order to lubricate the sliding surfaces between the piston and slider, return low-temperature refrigerant gas returned from the cooling circuit is introduced toward the oil pan at the inner bottom of the cylinder body. The kinetic energy of the refrigerant gas causes the lubricating oil in the oil pan to scatter toward the sliding surface for refueling, and then the refrigerant gas in the body is supplied into the cylinder via the suction valve device installed at the top of the piston. There are known ways to do this.

However, according to this method, it is difficult to accurately scatter lubricating oil onto the sliding parts, so a large amount of lubricating oil must be constantly scattered into the compressor body.

As a result, the scattered lubricating oil mixes with the refrigerant gas and is always sucked into the cylinder in large quantities along with the refrigerant gas, which reduces compression efficiency and requires an oil pan to be installed in the compressor to seal in a large amount of lubricating oil. There were certain drawbacks.

Furthermore, when such a horizontally opposed compressor is used as a refrigerant compressor for a car cooler, the compressor is required to be small, lightweight, and durable because it is used in an engine room, etc. .

Therefore, the double-headed piston used in compressors can also be used under certain piston diameter and piston stroke conditions.
In order to downsize the compressor, it is required that the overall length of the piston be as short as possible, that the slider can always operate smoothly, and that it can be easily machined with high precision.

Therefore, the present invention has been made to solve the above-mentioned drawbacks and to satisfy the above-mentioned requirements, and it is possible to achieve good lubrication of the sliding surface between the opposing plane of the piston middle portion and the slider sliding surface without the need for a pump. The purpose is to provide a compressor that is compact and lightweight.

A feature of the present invention is that a part of the outer periphery of the head adjacent to the opening of the slider sliding hole 22 is removed to form a concave shape, and a pair of socket-shaped cavities 46.
46 forming a notch 24 . By forming 24 into a double-headed piston 3, a notched cavity 46 is created in which lubricating oil mixed with gas is agitated and atomized in the space 26 inside the cylinder body 2 and is generated as the slider 4 reciprocates. , 46 efficiently adheres to the sliding surface 16.16 of the slider 4 exposed facing the cavity 46.46, and as the slider 4 retreats, the sliding surface between the piston 3 and the slider 4 This is because the lubricating oil adhering to the sliding surfaces 16, 16 is drawn in.

Hereinafter, the configuration of an embodiment of the present invention will be explained with reference to the drawings.

FIG. 1 shows a double-headed piston 3 according to an embodiment of the present invention.
This figure represents a horizontally opposed refrigerant compressor for automobile air conditioning, in which two No. 3 refrigerant compressors are arranged in parallel.

In the figure, reference numeral 1 denotes a steel drive shaft 7, on which two eccentric cam portions 10 and 10 are integrally formed with a phase difference of 180°.

This drive shaft 1 has a surface hardness of H to improve the wear resistance of the eccentric cam parts 10, 10.
It is carburized and quenched to an Ro of about 58 to 62.

The piston 3 is made of aluminum alloy, and has piston heads 19 directed outward at both ends in the axial direction, as shown in FIG.
．． 19 and four pillars 20 and 2 that connect its two heads.
0, 20, and 20, and both heads and each pillar are integrally formed by die-casting or the like.

Reference numeral 4 denotes an integrated slider, which is attached to the outer periphery of the eccentric cam parts 10, 10.

As shown in FIG. 5, the slider 4 is configured in the form of a sliding piece, with an annular bush 14 on its inner periphery and a substantially rectangular parallelepiped-shaped holder 15 that holds it on its outer periphery.

The bushing 14 of the slider is made of a cylindrical material made of bronze, leaded bronze, aluminum alloy, etc., which has good sliding characteristics such as seizure resistance, wear resistance, and low sliding resistance with respect to the eccentric cam part 10 made of steel. Alternatively, it may be formed into a cylindrical shape using a rolled bushing whose backing metal surface is made of steel or the like and lined with bronze, leaded bronze, aluminum alloy, etc.

The slider holder 5 is made of steel, and is designed to improve sliding characteristics such as seizure resistance, wear resistance, and low sliding resistance with respect to the aluminum alloy piston 3.
The sliding surface is carburized and quenched so that the surface hardness is approximately HRO 58 to 62.

The sliding surface 16 that slides on the piston of the slider 4 has
As shown in FIG. 5, an X-shaped oil groove 18 is formed along the slider sliding direction.

Further, a threaded oil groove 49 is formed on the inner circumference of the slider 4 that slides on the eccentric cam portion.

2 is a cylinder body, and as shown in FIG. 6, there are two parallel cylinders 25 into which pistons 3, 3 are slidably inserted.
, 25 are formed to penetrate in the horizontal direction.

Further, in this cylinder body 2, a cavity for penetrating the drive shaft 1 is formed in the cylinder 25 as a space 26 in the body from which excess thickness has been removed in order to reduce the weight of the body.
．． It is formed to penetrate in the horizontal direction so as to be orthogonal to 25.

The cylinder body 2 is formed by casting steel or aluminum alloy, and is then finished by ordinary cutting and grinding.

Reference numerals 7 and 8 denote front and rear lids made of aluminum alloy that are attached to the openings at both ends of the space portion 26, and bearings 11 and 12 that rotatably support the drive shaft 1 are mounted on the inner periphery of each. .

Reference numeral 9 denotes a shaft sealing member attached to the inner periphery of the front lid 7, which closes off the inside and outside of the body.

On the cylinder opening end surfaces 29, 29 of the cylinder body 2,
Each is equipped with a valve device.

This valve device has a valve seat plate 6 made of steel or aluminum alloy, as shown in FIG. 4 showing the tV-■ cross section of FIG.
cylinder 26. 26, a substantially annular suction hole 36 and a discharge hole 38 are provided on the inner diameter side of the suction hole 36, and a circular suction valve plate 41 and a discharge valve plate with a smaller diameter are provided corresponding to the holes 36, 38 of the valve seat plate 6. 42 is fixed and set at the center, and the outer peripheral side of each valve plate is curved to open and close in response to the return movement of the piston 3.

Further, on the valve seat plate 6, a valve cover 5 made of aluminum alloy having discharge gas chambers 39, 39 and a suction gas chamber 35 is attached to the cylinder body 2 via a sheet packing with a plurality of bolts 50. By tightening and fixing, the discharged gas is prevented from escaping into the suction gas chamber 35.

37 is a gas chamber partition wall that partitions the discharge gas chambers 39, 39 and the suction gas chamber 35.

Next, the cylinder body 2 will be explained in detail.

The cylinder body 2 (hereinafter referred to as body 2) has an inlet 30 for introducing return refrigerant gas from the cooling cycle (not shown) into the internal space 26, and an exhaust port 30 for sending the refrigerant gas to the cooling cycle. An outlet 33 is integrally formed to protrude from the outer periphery of the upper part.

As is clear from FIG.
7 into a space 26 in the body, and the space 26 extends parallel to the cylinder axis into the upper fan-shaped section 45, 45 between the parallel cylinders 25, 25.
A suction gas passage 31. having a substantially triangular cross section is formed through the suction gas passage 31.
31, the suction gas chamber 35.3 in both valve covers 5, 5
5.

The suction gas passages 31, 31 communicate with the space 26 in the body 2 at intermediate portions in the cylinder axis direction.

The valve seat plates 6, 6 are provided with substantially triangular communication holes 34. 34 is shown in Figure 41
It is formed like this.

On the other hand, the discharge port 33 is a discharge gas passage formed in a tunnel shape and protruding above the body upper wall 27 so as to pass through the body 2 above the suction gas passages 31, 31 in parallel with the suction gas passage 31. The discharge gas chamber 39. It leads to 39.

Note that elongated holes 40, 40 are formed in the valve seat plates 6, 6 in correspondence with the elongated grooves of the discharge gas passage 32, as shown in FIG.

In addition, in the figure, 43 is a service valve on the low pressure side.
It communicates with the body inner space portion 26, and 44 is a service valve on the high pressure side and communicates with the discharge gas passage 32.

28 is the bottom wall of the body, and fins are formed on the outer periphery.

Next, regarding the piston 3, FIGS.
This will be explained in detail using figures.

A sliding hole 22 for the slider 4 and a through hole 21 for the drive shaft 1 are formed in the piston 3 at the center between both piston heads, passing through the piston 3 in a direction perpendicular to the piston axis and intersecting with each other. has been done.

Of the inner circumferential surface of this slider sliding hole 22, parallel opposing planes 23 and 2 facing each other inside both piston heads 19 and 19.
3 is formed such that the spacing between the opposing faces is such that the slider 4 can slide smoothly.

The width of the opposing planes 23, 23 in the slider sliding direction is appropriately narrower than the sliding movement width of the slider 4.

And the ends of the slider sliding direction of the opposing planes 23 and 23 are as follows:
Notch portion 24 formed by removing a portion of the outer periphery of the adjacent head into a concave shape. I am facing the 24th.

The notch 24 is formed so that its width is approximately equal to the width of the slider sliding hole 22, and its depth from the outer periphery of the piston becomes gradually shallower toward the top of the piston.

On the other hand, the width of the drive shaft through hole 21 in the slider sliding direction is formed to be slightly wider than the width of the slider 4 in the same direction as shown in FIG. Hole 21. The slider 4 can be inserted from there.

Note that the pillar 20 needs to have a sufficient thickness within the diameter of the piston head in order to ensure appropriate strength.

Further, side plates 13, 13 made of aluminum are screwed to the side surfaces of the piston-facing planes 23, 23 in the drive shaft penetrating direction to prevent the slider 4 from slipping off using screws 51.

The piston head 19 is equipped with a piston ring 52 made of general steel or tetrafluoroethylene resin, for example, made by Toyo Bearing Co., Ltd. under the trade name Rulon.

By adopting the above shape and structure, especially when the body 2 and the valve seat plate are made of aluminum alloy, the discharge amount can be increased to 120.
The weight of a cc horizontally opposed compressor is approximately 3.2Kg,
The weight of a swash plate compressor for automobile air conditioning with approximately the same discharge amount is about 4.9 kg to about 6.9 kg. Since it weighs approximately 2 kg, it was possible to make it extremely small and lightweight.

Further, the durability is also sufficiently satisfactory, as will be clear from the following explanation regarding the lubrication of the sliding surfaces of the piston 3 and the slider 4 in the operation of the compressor.

Next, the operation of the compressor will be explained.

Prior to operation of the compressor, the space 26 in the body 2 is filled with an appropriate amount of lubricating oil L from the inlet 30, and the refrigerant gas 5 is sealed in the compressor and cooling circuit.

Note that a known electromagnetic clutch (not shown) is attached to the front part of the compressor main body.

When the rotation is transmitted to the drive shaft 1 through the electromagnetic clutch, the rotation of the drive shaft 1 causes the slider 4 attached to the eccentric cam portion 10 to move relative to the axial center of the drive shaft 1, as shown in FIG. Change position.

The slider 4 is restricted from moving in a direction perpendicular to the drive shaft 1 by a double-headed piston 3, and has a plane 23. Only directional changes along 23 are allowed.

The movement of the slider 4 in the drive shaft axis direction is controlled by the side plates 13,
13.

On the other hand, the piston 3 is slidably fitted to the cylinder 25, and as a result, as the eccentric cam portion 10 rotates, the slider 4 moves relative to the piston in the penetrating direction of the slider sliding hole 22 while moving the piston 3 into the cylinder. Move it back and forth inside.

Therefore, as the drive shaft 1 rotates, the piston 3,
3 reciprocates within the cylinders 25, 25, and the cylinder 2
5. Refrigerant gas is alternately sucked into and discharged into 25 via a valve device.

At this time, low-pressure refrigerant gas flows from the inlet 30 into the space 26 in the body through the inlet, as shown by the dashed line in FIG.

The refrigerant gas that has flowed into the space portion 26 cools the inside of the body because the liquid refrigerant remaining in the gas is vaporized and the temperature is low.

The refrigerant gas flowing into this space portion 26 flows through the upper fan-shaped cross section portion 45 . From the left and right suction gas passages 31, 31 formed by penetrating through 45, the suction gas chamber 3 in the valve covers on both sides
5,35.

Also, the discharge gas chamber 39 inside the valve cover. The high-pressure refrigerant gas discharged to 39 is sent out from the elongated hole 40 of the valve seat plate 6 through the discharge gas passage 32 and from the discharge port 33, as shown by the two-dot chain line in FIG.

Next, the piston facing plane 23. Regarding the lubrication of the sliding surfaces between 23 and the slider sliding surfaces 16, 16, FIGS. 7 to 11 are used to show step-by-step the process of one drive shaft 1 making one rotation in the direction of the arrow from the state shown in FIG. 3. This will be explained in detail.

As is clear from these figures, the slider 4 is moved by the rotation of the drive shaft 1 to the opposing planes 23 . It reciprocates between 23.

At this time, the slider 4 has a notch 24 on the outer circumferential side of the piston. 24 is formed in a concave shape, so that the side surfaces 17, 17 in the sliding direction protrude beyond the end of the opposing plane 23.

As the slider 4 reciprocates, gas moves in and out of the slider sliding hole 22 of the piston.

At the same time, a socket-shaped cavity 4 formed by opposing the circumferential wall surface of the piston notch 24 and the inner circumferential wall surface of the cylinder 25
6.46, a part of the gas displaced by the slider 4 collides with the body wall, detours, and enters the cavities 46, 46 as shown by arrow A, so that the gas in the cavity 46.46 Turbulent flow as shown in B occurs.

That is, the openings of the slider sliding holes 22 are opposed to the upper and lower walls 27 and 28 of the cylinder body, and the outer peripheral surface of the piston 3 is opposed to the wall surfaces of the body walls 27 and 28 in close proximity to each other.

Therefore, some resistance is added to the gas displaced by the slider flowing into the wide body space 26 on the outer circumferential side of the piston. The gas detours into the cavity 46, 46 as shown by arrow A, and the gas flows turbulently in the cavity 46, 46 as shown by arrow B.

Furthermore, as described above, lubricating oil L is sealed in the bottom of the space 26 in the body 2, but most of the lubricating oil is agitated and atomized by the kinetic energy of the incoming gas, piston 3, slider 4, etc. is mixed into the refrigerant gas and dispersed within the space portion 26.

That is, the inner surface of the POD bottom wall 28 and the outer circumferential surface of the piston 3 face each other at a close position, and the lower part of the piston 3 is in contact with the lubricating oil L before the compressor starts operating, or is lubricated immediately after the compressor starts. The ripples on the oil surface make it accessible.

Therefore, most of the lubricating oil is stirred and atomized within the space 26 by the reciprocating motion of the piston and the kinetic energy of the refrigerant gas immediately after the compressor is started, and is agitated into a gas-oil mixed gas (hereinafter referred to as mixed gas). exists as qi).

Note that a portion of the atomized and dispersed lubricating oil L is circulated through a cooling circuit and a compressor (not shown).

First, as shown in FIGS. 3, 7, and 8, as the slider 4 descends, the air-fuel mixture is sucked into the space 47 above the slider sliding hole 22 from the space 26 on the outer periphery. In the space 48, the outer space portion 2
The air-fuel mixture is discharged to 6.

Further, in the lower space 48, the air-fuel mixture pushed away by the slider is transferred to the wide body space portion 26 on the outer circumferential side of the piston.
The displaced air-fuel mixture is likely to be compressed slightly as it encounters some resistance to flow into the air.

Therefore, the gas pressure in the lower space 48 becomes higher than that in the outer circumferential space 26 due to the movement of the slider 4 that operates like a piston, and the lubricating oil concentration in the mixture in the lower space 48 decreases as the slider 4 descends. It is thought that as the temperature increases, the air-fuel mixture becomes higher than that existing in the outer space 26.

At this time, as the slider 4 descends, the mixture with high lubricating oil concentration is displaced as shown in arrow B in the socket-shaped cavity 46.46 of the notch 24.24, as shown in FIG. turbulent flow is generated, and the opposing plane 23,
The air-fuel mixture is made to collide with the sliding surface 16.16 of the slider 4 exposed beyond the end of the slider 4 facing the cavity 46.46, and the lubricating oil is efficiently applied to the sliding surfaces 16, 16.

Similarly, in the upper space 47, as the slider 4 rises as shown in FIGS. 9 and 10 due to the subsequent rotation of the drive shaft 1, the lubricating oil concentration in the air-fuel mixture increases.
In the cavities 46, 46 of the notches 24, 24, arrow B
A turbulent flow as shown in is generated, and the lubricating oil is efficiently adhered to the sliding surfaces 16, 16 of the slider 4 exposed opposite to the cavities 46, 46.

Also, the sliding surfaces 16, 16 of the slider 4 exposed in this way
As the slider 4 continues to retreat as shown in FIG. 11, the lubricating oil l adhering to the lubricating oil l is drawn into the sliding surface between the opposing flat surfaces 23, 23 of the piston and the sliding surfaces 16, 16 of the slider, and
Lubricate its sliding surfaces.

At this time, as shown in FIG. 5, the sliding surface 16 of the slider
, 16 are formed with oil grooves 18, 16, the lubricating oil l can be drawn into the sliding surface more efficiently.

In the above embodiment, the explanation was given using drawings in which the piston is reciprocating in the horizontal direction, but experiments have shown that the same results can be obtained even when the illustrated compressor is operated with the piston reciprocating in the vertical direction. A lubricating effect was obtained.

As described above, the present invention provides a horizontally opposed compressor in which a part of the outer periphery of the head adjacent to the opening of the slider sliding hole is removed in a concave shape to form a socket-shaped cavity with the opposing wall surface of the cylinder body. By forming the notch in the double-headed piston, the lubricating oil stirred and atomized in the space of the cylinder body is opposed to the cavity by the turbulent flow in the notch that occurs as the slider reciprocates. The lubricating oil adheres efficiently to the exposed sliding surface of the slider, and as the slider retreats, the lubricating oil adhering to the sliding surface of the piston and slider is drawn into the sliding surface of the piston and slider, even without the need for a pump. Good lubrication of the sliding surface between the opposing plane of the piston intermediate portion and the slider sliding surface can be achieved.

[Brief explanation of the drawing]

The drawings show a horizontally opposed refrigerant compressor for automobile air conditioning in which two double-headed pistons are arranged in parallel according to an embodiment of the present invention. (representing a cross section) cross-sectional front view. FIG. 2 is a cross-sectional plan view showing the section 1-1 of FIG. 1. FIG. 3 is a cross-sectional side view showing the section 1-1 of FIG. 1. FIG. 4 is a sectional view of the valve device portion taken along the line IV-IV in FIG. 2; FIG. 5 is a perspective view showing the piston and slider. FIG. 6 is a perspective view of the cylinder body. 7 to 11 are cross-sectional side views showing stepwise a process in which the drive shaft rotates once in the direction of the arrow from the state shown in FIG. 3. Explanation of symbols, 1... Drive shaft, 2... Cylinder body, 3... Piston, 4...
・Slider, 10...Eccentric cam part, 19...
... Piston head, 21 ... Drive shaft through hole,
22...Slider sliding hole, 23...Opposing plane, 24...Notch, 25...
Cylinder, 27... (cylinder body) upper wall,
28... (cylinder body) bottom wall, 46...
...Cavity, L...Lubricating oil, A...(
arrow B, representing gas detouring into cavity 46;
. . . (representing turbulent gas flow in the cavity 46), arrow, l . . . (adhering to the sliding surface 16) lubricating oil.

Claims (1)

[Claims] 1 The double-headed piston 3 slidably fitted into the cylinder 25 of the cylinder body 2 rotates the drive shaft 1, which passes through the intermediate portion of the piston in a direction perpendicular to the piston axis. In a horizontally opposed compressor that is reciprocated by a slider 4 mounted on the piston 3, a slider is provided in the piston 3 that passes through the piston in a direction perpendicular to the piston axis at a central portion between both piston heads 19 and 19 and intersects with the piston. The slide hole 22 and the drive shaft through hole 21 are formed, and parallel opposing planes 23 . 23
A part of the outer periphery of the head 19 adjacent to the opening of the slider sliding hole 22 is removed into a concave shape so that the width of the slider in the sliding direction is appropriately smaller than the sliding width of the slider 4. A cylinder body wall 27.2 is provided with notches 24, 24, 24, 24 to constitute a pair of cavities 46.46, and further faces the opening of the slider sliding hole 22.
The wall surface of 8 and the outer circumferential surface of the piston 3 are opposed to each other at a close position, thereby creating a space 2 inside the cylinder body 2.
The lubricating oil stirred and atomized in the notch cavities 46 and 4 is generated as the slider 4 reciprocates.
6. A horizontally opposed compressor, characterized in that the turbulent flow within the horizontally opposed compressor 6 efficiently adheres to the sliding surfaces 16, 16 of the slider 4 exposed facing the cavity 46, 46.