JPH0326877A - Reciprocating type compressor - Google Patents

Abstract

PURPOSE:To prevent the trouble generated by the overheat due to the excessively compressed air with the simple constitution, by interlocking a flyweight with an eccentric ring by an interlocking mechanism and urging an elastic member towards the center of turn of a crankshaft. CONSTITUTION:The discharge quantity of the compressed air increases as the engine revolution speed increases. The centrifugal force F generated around a crankshaft 2 increases as the revolution speed of the crankshaft 2 increases. A flyweight 6 is turned in the direction separating from the crankshaft 2b of the crankshaft 2, overwhelming the urging force (f) of a coil spring 9. Then, the flyweight 6 turns an eccentric ring 7 by an interlocking mechanism 8. Therefore, the distance (l) between the center A of turn on the crank pin 2c side of a connecting rod 3 and the center B of turn of the crankshaft 2 is reduced by this turn in proportion to the revolution speed of the engine, and the stroke L of a piston 4 is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a reciprocating compressor that compresses air using a crank mechanism, and particularly to a reciprocating compressor equipped with a variable displacement mechanism.

[Prior Art] Conventionally, vehicles such as trucks and buses are equipped with a compressor that generates compressed air to operate air cylinders used for opening and closing doors. A reciprocating compressor is generally used, in which a piston moves back and forth in a cylinder equipped with intake and exhaust valves to compress air, and is directly driven by an engine.

[Problem to be solved by the invention] Conventional reciprocating compressors are configured as described above, and are directly connected to the engine, so if the optimal air discharge rate is set at low engine speeds, excessive air output occurs at high engine speeds. of compressed air is generated, which not only causes an unnecessary loss of engine output, but also causes an unnecessary temperature rise in the compressor, causing compressor malfunctions such as carbonization of the hydraulic oil. Additionally, if the setting is made to obtain the optimum air discharge amount at high speeds, there is a problem in that air may be insufficient at low speeds.

Therefore, as described in Japanese Patent Application Laid-Open No. 61-291739, an eccentric ring whose inner and outer circumferences are eccentric from each other is provided between the crankshaft and the connecting rod of a reciprocating compressor. The stroke of the piston is changed by rotating it with hydraulic pressure to obtain the optimal air discharge amount at low rotations, and the piston stroke is reduced at high rotations to lower the compression capacity and compression ratio.
There is a reciprocating compressor that is equipped with a variable compression ratio mechanism that can reduce the amount of air discharged compared to the engine speed.

However, since oil pressure is required to operate the variable compression ratio mechanism, the structure is not only complicated, but also there are problems such as loss of engine output in order to obtain this oil pressure.

This invention was made to solve the above-mentioned problems, and provides a reciprocating compressor that can change the discharge amount of compressed air with a simple structure without reducing the engine output. The purpose is to

[Means for Solving the Problems] A reciprocating compressor according to the present invention includes a cylinder equipped with intake and exhaust valves, a crankshaft that transmits rotational force from a drive source, and one end of which is pivotally connected to the crankshaft. It consists of a connecting rod that converts rotational motion into reciprocating motion, and a piston that is pivotally connected to the other end of the connecting rod and reciprocates within the cylinder, and has an outer circumferential surface and an inner circumferential surface that are eccentric to each other. , an eccentric ring whose outer peripheral surface is attached to the bearing hole of either the crankshaft or the connecting rod, and whose inner circumferential surface is attached to the other shaft; The crankshaft has a flyweight that rotates away from the center of rotation, an interlocking mechanism that connects the flyweight to the eccentric ring, and an elastic member that biases the flyweight toward the center of rotation of the crankshaft. .

[Function] The reciprocating compressor according to the present invention includes an eccentric ring having an outer circumferential surface and an inner circumferential surface eccentric to each other, a flyweight that rotates away from the center of rotation of the crankshaft, and a flyweight that rotates away from the center of rotation of the crankshaft. An interlocking mechanism that interlocks with the eccentric ring and an elastic material that urges the flyweight toward the center of rotation of the crankshaft cause the flyweight to move away from the center of rotation of the crankshaft in proportion to the engine speed, thereby reducing the eccentricity. The rings are rotated by the interlocking mechanism to shorten the stroke of the piston, lowering the compression capacity and compression ratio, and reducing the amount of compressed air delivered per stroke of the piston.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 11i1 to 5. In the figure, 1 is a cylinder equipped with an intake and exhaust valve (not shown) at the top, 2 is a crankshaft that transmits rotational force from a drive source such as an engine, and 3 is one end that is pivotally connected to the crankshaft 2 and rotates back and forth. A connecting rod 4 is pivotally connected to the other end of the connecting rod 3 via a piston pin 5, and a piston 7 reciprocates within the cylinder. 6 is an eccentric ring having an inner circumferential surface 7a rotatably attached to the crank pin 2C of the crankshaft 2, and an outer circumferential surface 7b rotatably attached to the bearing hole 3a of the connecting rod 3; A flyweight 9 is pivotally attached to the balance weight 2a of the shaft 2 and rotates away from the crankshaft 2b, which is the rotation center B, by the centrifugal force F generated by the rotation of the crankshaft 2.
This is a coil spring as an elastic member that urges the crankshaft 2b in the direction of the crankshaft 2b. Crankshafts 2b at both ends of the crankshaft 2 are pivotally connected to the casing 10 via bearings, etc., and one crankshaft 2b is mechanically connected to the output shaft of the engine to transmit the rotation of the engine. The eccentric ring 7 is formed into a cylindrical shape having a flange 7c at one end, for example, as shown in FIG. 4, and is made of a bearing material such as white metal. Further, a rack gear 7d is formed along the periphery of the collar 7c at a position facing the gear 6a provided at one end of the flyweight 6, and the interlocking mechanism 8 is constituted by this gear 6a and the rack gear 7d.
The coil spring 9 is a tension spring, and one end is attached to the other end of the flyweight 6, and the other end is attached to the balance weight 2a of the crankshaft 2.

Next, the operation will be explained. First, when the engine (not shown) is not started, the coil spring 9 positions the flyweight 6 closest to the crankshaft 2b, as shown in FIG.

At this time, in the eccentric ring 7, the narrowest point between the inner circumferential surface 7a and the outer circumferential surface 7b is located below the bearing hole 3a of the connecting rod 3. That is, the center A of the connecting rod 3 on the crank pin 2C side and the crankshaft 2
The piston 4 is located at a distance l from the center of rotation B, and the stroke L of the piston 4 is the longest. Next, when the engine is started, the crankshaft 2 rotates around the crankshaft 2b, and the crank pin 2c rotates eccentrically, as shown in FIG. The piston 4 reciprocates within the cylinder 1 by the connecting rod 3, sucks air into the cylinder 1 during the downward stroke of the piston 4, compresses the air sucked in during the upward stroke, and discharges it from the cylinder 1. As mentioned above, the discharge amount Q of compressed air increases as the engine speed V increases, but as the rotation of the crankshaft 2 increases, the centrifugal force F generated around the crankshaft 2 increases. ，
This centrifugal force F causes the flyweight 6 to overcome the biasing force f of the coil spring 9 and rotate in a direction away from the crankshaft 2b of the crankshaft 2. The above flyweight 6 has an interlocking mechanism 8 (gear 6a and rack gear 7d)
rotates the eccentric ring 7, and as the eccentric ring 7 rotates, the rotation center A of the connecting rod 3 on the crank bin 2c side and the rotation center B of the crankshaft 2 are rotated.
The distance 1 between the piston 4 and the piston 4 becomes narrower in proportion to the rotational speed of the engine, and the stroke L of the piston 4 becomes shorter. In other words, the compression capacity and compression ratio decrease in proportion to the engine speed V, and the discharge amount Q of compressed air per stroke decreases.
As shown in Fig. 5, the compressed air discharge amount Q during high engine rotation can be reduced compared to the conventional method. The above configuration makes it possible to reduce wasted compressed air when the engine rotates at high speeds, thereby preventing unnecessary loss of engine output due to excess compressed air and eliminating unnecessary temperature rises in the compressor. It is possible to prevent compressor malfunctions due to carbonization of hydraulic oil.

In addition, in this embodiment, the outer circumferential surface 7b of the eccentric ring 7
into the bearing hole 3a of the connecting rod 3, and the inner peripheral surface 7
a is attached to the crank pin 2c of the crankshaft 2, but a pin may be provided on the connecting rod 2, a bearing hole may be provided on the crankshaft 3, and the eccentric ring 7 may be attached to the pin and the bearing hole.

Further, in this embodiment, the interlocking mechanism 8 is composed of the gear 6a of the flyweight 6 and the rack gear 7d of the eccentric ring 7, and the elastic material is made of the coil spring 9, but the elastic material is not limited to this. Even if the interlocking mechanism is configured using a link mechanism, a cam mechanism, etc., the same effect can be obtained.

Further, as shown in FIG. 6, a flyweight 60 may be provided directly on the eccentric ring 70, and in this case, the flyweight 60 rotates about the crank pin 2c of the crankshaft 2.

[Effects of the Invention] As described above, according to the present invention, the reciprocating compressor has the following advantages:
an eccentric ring having an outer circumferential surface and an inner circumferential surface eccentric to each other; a flyweight that rotates away from the center of rotation of the crankshaft; an interlocking mechanism that interlocks the flyweight with the eccentric ring; and the flyweight. Since the piston l is provided with an elastic member that biases the piston l toward the center of rotation of the crankshaft, the piston l moves in proportion to the engine rotation speed without reducing engine output.
The amount of compressed air discharged per stroke can be reduced, and problems caused by overheating of the compressor due to excessive compressed air can be prevented.

[Brief explanation of drawings]

Figures 1 to 3 are a front sectional view and a side sectional view of a reciprocating compressor according to an embodiment of the present invention, Figure 4 is an external perspective view of an eccentric ring of this embodiment, and Figure 5 is an embodiment of the present invention. FIG. 6 is a side sectional view of another embodiment of the reciprocating compressor. 1...Cylinder, 2...Crankshaft, 3...
・Connecting rod, 4... Piston, 6...
Flyweight, 7... Eccentric ring. 7a...Inner circumferential surface, 7b...Outer circumferential surface, 8...Interlocking mechanism, 9...Coil spring.

Claims (1)

[Claims] A cylinder equipped with intake and exhaust valves, a crankshaft that transmits rotational force from a drive source, a connecting rod whose one end is pivotally connected to the crankshaft and converts rotational motion into reciprocating motion, and the other end of this connecting rod. A reciprocating compressor comprising a piston that is pivotally mounted and reciprocates within the cylinder, and has an outer circumferential surface and an inner circumferential surface that are eccentric to each other, and the outer circumferential surface is used as a bearing for either the crankshaft or the connecting rod. an eccentric ring that is attached to the hole and whose inner peripheral surface is attached to the other shaft; a flyweight that rotates away from the center of rotation of the crankshaft due to the centrifugal force generated by the rotational movement of the crankshaft; A reciprocating compressor, comprising: an interlocking mechanism that interlocks a weight with the eccentric ring; and an elastic member that biases the flyweight toward the center of rotation of a crankshaft.