JPS599107Y2 - Horizontally opposed compressor piston - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a piston structure for a horizontally opposed compressor in which a double-headed piston reciprocates within a cylinder.

As shown in FIGS. 1 to 3, a horizontally opposed compressor has a double-headed piston 9 slidably fitted into a cylinder, and a crankshaft 2 that passes through an intermediate portion of the piston in a direction perpendicular to the piston axis. Due to the rotation, the eccentric portion 3a of the crankshaft 2
and sliders 4a and 4b that are slidably fitted on the outer periphery of the eccentric portion 3b.
5a and 5b, the suction gas is compressed and discharged.

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 installed in an engine room.

Therefore, the double-headed piston used in compressors can also be used under certain piston diameter and piston stroke conditions.
In addition to reducing the overall length of the piston as much as possible to make the compressor smaller, it is also required that the piston be lightweight and rigid, that the slider can operate smoothly, and that it can be easily machined with high precision.

Therefore, the present invention was developed based on the above-mentioned requirements for a double-headed piston, and its feature is that a notch plane is provided on the front and rear surfaces in the penetration direction of the sliding hole through which the crankshaft of the double-headed piston passes. In addition, a side plate having a through hole formed in the center is adapted to the plane of the notch.

The structure of an embodiment of the present invention will be explained below with reference to the drawings.

1 to 3 show a horizontally opposed compressor 1 equipped with a double-headed piston 9 according to the present invention.

In the figure, 2 is the crankshaft, and there are two eccentric parts 3 on the shaft.
a and 3b are shaped with a phase difference of 180° in the circumferential direction.

4a and 4b, 5a and 5b are each a pair of divided sliders, and are held so as to be able to slide relative to the crank eccentric parts 3a and 3b so as to sandwich the crank eccentric parts 3a and 3b.

The sliders 4a and 4b, 5a and 5b have a semi-cylindrical cylindrical surface on the inner periphery that slides on the crank eccentric parts 3a and 3b, and a flat cylindrical surface that slides on the piston 10 on the outer periphery facing the cylindrical surface. The plane is 8.

Reference numeral 6 denotes a cylinder block, through which two parallel cylinders 7, 7 through which the piston 9 is slidably inserted are formed.

As more clearly seen in FIGS. 4 to 6, the piston 9 has a double-headed piston body 10 integrally formed with piston heads 11 and 12 directed outward at each axial end. and two side plates 16 and 17 arranged opposite to each other on the outer peripheral side surface of the piston body 10.

A sliding hole 13 for sliders 4a, 4b, 5a, and 5b is formed in the piston body 10 at the center between both piston heads and passes through the piston body 10 in a direction perpendicular to the piston axis.

Of the inner peripheral surface of this sliding hole 13, both piston heads 11.
The opposing surfaces serving as the inner opposing surfaces of 12 are sliders 4a and 4b.
, a pair of parallel surfaces 21 on which the outer peripheral surfaces 8 of 5a and 5b slide together.
．． 22, and the other radially opposing surface is a slider 4.
The side surfaces of a, 4b, 5a, and 5b face each other at a position appropriately separated from the slider side surface so that they do not come into contact with each other during slider movement.

The piston body 10 also has a notch plane 14 on the front and rear surfaces in the penetrating direction of the sliding hole 13, which is perpendicular to the sliding hole. 15 is extended to the vicinity of the tips of both piston heads 11 and 12.

That is, the notch plane 14. 15 is the piston body 10
In order to prevent the side plates 16, 17 from protruding beyond the circumference of the piston head when the side plates 16, 17 are attached to the outer circumference of the piston body 10, a pair of parallel surfaces are formed by cutting out the outer circumference of the piston body 10. It is given the appearance of being established.

Furthermore, in the piston main body 10, both the piston heads 11 are connected as one body by the pillars 23 and 24 left on the radial side surface of the sliding hole 13, as described above.

The side plates 16 and 17 attached to the piston body 10 have a flat plate shape whose length in the piston axis direction is greater than the length between the parallel surfaces 21 and 22, and whose width in the direction perpendicular to this is equal to or less than the width of the cutout planes 14 and 15. Through holes 18 and 19 for passing through the crankshaft 2, which are smaller than the sliding hole 13, are formed in the center thereof.

Note that depending on the shape of the crankshaft, the through hole 18. A slope extending outward is provided on the circumferential edge of the piston 19 in the axial direction to prevent unnecessary contact between the crankshaft 2 and the side plates 16 and 17.

The side plates 16 and 17 align the through holes 18 and 19 concentrically with the sliding hole 13 and form the cutout plane 14 of the piston body 10. 15, and both ends of the side plates 16, 17 in the piston axial direction are connected to both piston heads 11. 12 with screws 20, 20, 20, 20.

Therefore, the peripheral edges of the through holes 18 and 19 of the side plates 16 and 17 are located closer to the center of the through hole than the peripheral edge of the sliding hole 13, that is, on the inner diameter side of the sliding hole 13.

Next, the processing and assembly of the piston 9 will be explained. The piston body 10 is formed into one piece by, for example, aluminum die-casting, and then the head 11,
The outer periphery of 12 is ground, and the parallel surfaces 21 and 22 in the sliding hole 13 are
Finishing is done by broaching or other means to remove the finishing allowance made during the shaping process.

Therefore, compared to a case where both piston heads are not formed into one body, both piston heads 11. High processing accuracy such as concentricity of 12 and parallelism of parallel surfaces 21 and 22 can be easily obtained.

One side plate 17 of the side plates 16 and 17 is attached to the piston body 10 before the piston body 10 is inserted into the cylinder 7, and the other side plate 16 is attached to the piston body 10 inserted into the cylinder 7. Slider 4a in hole 13
, 4b, 5a, 5b are inserted, then the piston body 1
0.

In this way, both side plates 16 are attached to the piston body 10. 17, the piston 9 has both heads 11 and 12.
However, not only the legs 23 and 24 but also the side plate 16. 17, which significantly increases its rigidity.

Also, when inserting the piston body 10 into the cylinder 7,
Since the side plate 17 is within the diameter of the piston head, it can be inserted from the open end of the cylinder 7 without any hindrance.

In this regard, in conventional double-headed pistons, the pillars were thickened to increase the strength of the double-headed piston, but if the pillars were made thicker inside the sliding hole, the momentum of the slider would be narrowed, and the width of the slider would be reduced. There is a drawback that it has to be made smaller, and if the pedestal is made thicker on the outer periphery of the sliding hole, that part cannot fit into the cylinder, so the overall length of the piston becomes longer, and for convenience of assembly, the cylinder block must be split. There are some disadvantages such as not being able to do so.

Next, the operation of the compressor will be briefly described. First, as the crankshaft 2 rotates, the divided sliders 4a and 4b, which are slidably engaged with the eccentric portion 3a, change their position with respect to the axis of the crankshaft 2.

The movement of the divided sliders 4a and 4b in a direction perpendicular to the crankshaft is restricted by a double-headed piston 9, and the piston 9 is allowed to change only in a direction along parallel planes 21 and 22.

Further, the movement of the divided sliders 4a, 4b in the axial direction of the crankshaft 2 is restricted by the side plates 16 and 17, and the deviation of the divided sliders 4a, 4b from the sliding hole 13 is also restricted by the side plates 16 and 17. ing.

In addition, since the side plates 16 and 17 are screwed to the piston heads 11 and 12, respectively, at their top ends in the piston axial direction, the slider 4a is attached to the side plates 16 and 17 during operation.
, 4b slide somewhat strongly, no deformation occurs that would impede the smooth movement of the sliders 4a, 4b.

Furthermore, the piston 9 is moved by guiding the sliders 4a and 4b by the side plates 16 and 17.
The piston itself no longer rotates with respect to the center axis of the piston.

Therefore, there is no accident such as the periphery of the sliding hole 13 of the piston coming into contact with the crankshaft 2 and damaging the pillars 23 and 24 of the piston as in the conventional case.

On the other hand, since the piston 9 is slidably fitted to the cylinder 7, as the crank eccentric part 3 rotates, the sliders 4a, 4
b makes a reciprocating movement within the cylinder 7, alternately drawing fluid into the compression space within the cylinder 7, compressing it, and then opening the discharge valve to discharge it.

In the above embodiment, the side plates on both sides are one pot, but it is also possible to use a side plate that is divided into two parts on the left and right in the diagonal direction of the piston axis. The two-headed piston body is made into two separate pieces and the piston body is made into one piece, so it can be easily machined with high precision.Also, the side plate is installed within the diameter of the piston head by cutting out the outer peripheral side of the center part of the double-headed piston body, so the slider It is easy to assemble the piston to the cylinder block without reducing the momentum or lengthening the overall length of the piston.Furthermore, both ends of the side plate in the axial direction of the piston are fixed to the piston head, so the legs are reinforced. This increases piston rigidity, does not cause deformation of the side plate, does not impede smooth movement of the slider, and prevents slider deviation.
Moreover, it has the effect of making the compressor smaller and lighter.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a cross-sectional front view (representing the section II in FIG. 2) of a horizontally opposed compressor equipped with a double-headed piston. FIG. 2 is a cross-sectional plan view taken along the line II--II in FIG. 1. FIG. 3 is an explanatory cross-sectional plan view showing a state in which the piston has been moved, with the same cross-section as that in FIG. 2; Figure 4 is a front view of the piston. FIG. 5 is a cross-sectional plan view taken along the line V-■ in FIG. 4. FIG. 6 is a cross-sectional side view showing the VI-VI cross section of FIG. 5. 9... Piston, 10... Piston body, 11.
12... Piston head, 13... (slider) sliding hole. 14, 15... Notch plane, 16. 17... side plate, 18. 19... (crankshaft) through hole.

Claims (1)

[Scope of utility model registration request] Piston heads 1 directed outward from each other at both axial ends
A double-headed piston body 10 in which 1.12 is integrally formed.
, both piston heads 11 of the piston body 10. 12
A sliding hole 13 passing through the piston body 10 in a direction perpendicular to the piston axis is provided in the center between the two, and cuts perpendicular to the sliding hole 13 are provided on the front and rear surfaces of the piston body 10 in the penetrating direction of the sliding hole 13. Notch plane 14. 15, and plate-like side plates 16 and 17 with through holes 18 and 19 smaller than the sliding hole 13 in the center thereof, and the through holes 18 and 19 of the side plates 16 and 17 are connected to the sliding hole 13. A piston for a horizontally opposed compressor, characterized in that both ends of the side plates 16 and 17 in the piston axial direction are fixed to both piston heads 11 and 12 concentrically.