JPH0730343U - Rotation control device for engine-driven compressor - Google Patents

Abstract

(57) [Summary] [Purpose] To suppress a sudden increase in rotation at the start of an engine-driven compressor and control the warm-up operation at an appropriate rotation speed. [Structure] In an engine-driven compressor that controls capacity and rotation by a speed regulator, a speed regulator that operates by air pressure and a speed regulator that operates by hydraulic pressure are provided at opposite positions of each rod and fixed to one rod. The operating rod is loosely fitted in the long hole of the connecting rod fixed to the rod of the other speed regulator, the governor rod connected to the operating rod operates the speed governor, and the hydraulic speed regulator increases the rotation immediately after the engine is started. It is configured to suppress and perform warm-up operation.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotation control device for an engine-driven compressor that reduces the load when starting the engine and stabilizes warm-up operation in a large compressor driven by an engine.

[0002]

[Prior art]

Conventionally, in this type of engine-driven compressor, an unloader device that controls the intake air capacity of the intake air adjustment valve of the compressor and a governor for controlling the engine rotation speed have been linked to discharge air from start to no-load operation. It is a known technique that a back load on the side is purged to a constant pressure to reduce the power load during this operation. For example, a device disclosed in Japanese Utility Model Laid-Open No. 3-92576 discloses a second cylinder which controls the operation of this piston cylinder by connecting the pressure of a piston cylinder for low speed rotation connected to a throttle lever of an engine to a compressor. The cylinders are arranged side by side, and the second cylinder is operated by the receiver tank pressure to suppress the movement of the low speed rotation cylinder. In general, in the case of a small engine-driven compressor (discharging amount of 30 m ³ / min or less), the pressure on the discharge side bypassed via the pressure regulating valve is directly applied to the diaphragm chamber of the intake regulating valve for capacity control, and the engine starts After that, there were many cases where the load was reduced at the start by warming up by balancing with the closing pressure of the pressure control valve. On the other hand, in a portable large engine-driven compressor (eg, discharge rate of 50 m ³ / min or more), the compressor itself often uses a motor-driven compressor, and a different compressor is used to drive the engine. The only option was to warm up the engine at startup.

[0003]

[Problems to be solved by the device]

 In general, a motor-driven compressor is started by the star delta method, and warm-up operation is not performed at low speed.Therefore, if the compressor is switched to motor drive instead of motor drive, it will rotate at high speed immediately after starting the engine. I will end up. In order to prevent such high speed rotation, the movement of the intake control valve is controlled so that the valve body of the compressor's intake control valve does not open when the engine is started, so the movement of the valve body is suppressed by the piston and spring from the opposite side. It has a structure that Therefore, immediately after the engine is started, air is not sucked in from the intake control valve, so the air piston cylinder for controlling the engine speed operates only with the air in the valve body and the bypass circuit, and it takes several tens of seconds for the engine to reach no load. In other words, during this period, the engine is driven at high speed, which imposes a heavy load on the engine and is not preferable for the engine. After starting the engine, it is generally necessary to warm up the engine until lubricating oil flows to each part of the engine.

Further, in the one disclosed in Japanese Utility Model Laid-Open No. 3-92576, the movement of the low-speed rotation cylinder can be freely moved by the action of the compressor, but the cylinder described above is accompanied by the pressure drop in the receiver tank. However, this does not provide sufficient control of warm-up operation. The purpose of this invention is to use two piston cylinders in the governor control system that controls the engine speed without changing the compressor starting load reduction device, and to prevent the engine from rising to high speed immediately after starting. In addition, the engine drive is designed to suppress the disturbance caused by the decrease in the no-load speed that occurs when the engine is started, to smoothly perform warm-up operation at an appropriate speed, and to promptly start up to high-speed rotation after warm-up operation. The present invention provides a rotation control device for a compact compressor.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides an engine-driven compressor in which an intake air regulating valve is provided in the compressor body and the capacity and rotation are controlled by the first speed regulator from the receiver tank via the pressure regulating valve, A second speed regulator that is operated by hydraulic pressure is provided so as to face the first speed regulator, and the speed regulators are connected by a bracket with an elongated hole, so that the first speed regulator and the second speed regulator are connected. It is characterized in that the governor lever of the engine is actuated by a relative motion with respect to, the engine speed is reduced immediately after the engine is started, and the warm-up operation is performed.

[0006]

[Action]

 In the engine-driven compressor of this invention, the first speed regulator and the second speed regulator are arranged to face each other, and the operation of the governor lever for controlling the rotation of the engine is performed by the first speed regulator connected to the receiver tank. Controlled by air. On the other hand, since the operation of the governor lever by the air control is adjusted by the second hydraulic speed regulator connected to the gear pump of the compressor, the rotation at the time of starting the engine can be easily suppressed with a simple mechanism and stabilized. Ideal warm-up operation is possible.

[0007]

【Example】

 Hereinafter, FIG. 1 is a schematic explanatory view of an engine-driven compressor incorporating the rotation control device of the present invention. FIG. 2 is an enlarged perspective view of a main part of the rotation control device of FIG. FIG. 3 is a sectional view showing the internal structure of the speed regulator. 4 (a), (b), (c), and (d) are operation explanatory views of the rotation control device of the present invention, and FIGS. 5 (a) and 5 (b) are the engine speed and the pressure in the receiver tank. 3 is a timing chart showing the relative relationship of

As shown in FIGS. 1 to 3, the first speed regulator 3 and the second speed regulator 4 connected to the governor rod 2 of the engine 1 are arranged to face each other. The first speed regulator 3 is for pneumatically actuated rated no-load operation, while the second speed regulator 4 is for hydraulically actuated startup warm-up operation. The piston rod 3a of the "rated / no-load operation" first speed regulator 3 is engaged with the governor rod 2 via a connecting member 5, and its end is connected to the governor lever 6 of the speed governor 7. It is connected. As shown in FIG. 3, the internal structure of these speed regulators has a slidable piston 21 inside a cylinder 20, a bellows 22 is mounted on this surface, and a spring 23 is fitted inside this piston 21. Rarely, the rod 24 of the piston 21 is constantly urged in a direction of pressing the rod 24. When air or oil, which is a pressure medium, is pressurized in the cylinder 20, the rod 24 is pushed against the elasticity of the spring 23. It is designed to be moved.

An idling stopper 8 having a long hole 8a is attached to the tip of the piston rod 4a of the second speed regulator 4 for "starting / warming up". A guide bar 9 protruding integrally with the connecting member 5 of the governor rod 2 is slidably and loosely fitted into the elongated hole 8a. Reference numeral 10 denotes an intake air control valve of the compressor 11, which has a normal diaphragm inside. A rod of a piston 12a elastically urged by an elastic member 12b is connected to the intake regulating valve 10 to form a load reducing device 12. The intake valve 10 is connected to a solenoid valve SV ₂ . A receiver tank 13 is connected to the compressor 11. The receiver tank 13 is in communication with the intake adjusting valve 10 or the first speed regulator 3 via a pressure adjusting valve 14. An electromagnetic valve SV ₁ and a manual valve 15 are arranged in parallel with the pressure adjusting valve 14. Reference numeral 16 is a discharge valve of the receiver tank 13. Reference numeral 17 is a radiator of the engine 1, and cooling air is blown by a fan 18. Reference numeral 19 is an air cleaner.

When the engine is started, the gear pump 11 a connected to the rear part of the compressor 11 is activated, the hydraulic pressure is applied to the second speed regulator 4, and at the same time, the load reducing device for the intake control valve 10 of the engine driven compressor 11 is activated. Hydraulic pressure is also applied to the piston 12a of 12 and the valve body 10a begins to open. The elongated hole 8a of the idling stopper 8 connected to the piston rod 4a of the second speed regulator 4 moves and operates in the direction to be released from the position of the starting rotation speed of the engine 1.

When the pressure in the receiver tank 13 reaches 2-3 kg / cm ² , the valve body 10a of the intake regulating valve 10 closes. At the same time, air pressure is applied to the first speed regulator 3, and the governor lever 6 of the speed governor 7 of the engine 1 is moved to the low speed side via the connecting member 5 and the governor rod 2. In this state, warm-up operation is performed until the time set by the electronic circuit.

The operation of the rotation control device of the present invention constructed as described above will be described based on an embodiment shown in the drawings. 1. Description of Operation Before Starting (1) The valve body 10a of the intake air regulating valve 10 is closed because the piston 12a is pushed by the elastic action of the elastic member 12b of the load reducing device 12. (2) The stroke of the second speed regulator 4 is set larger than that of the first speed regulator 3. The elastic constant K ₁ of the spring of the second speed regulator 4 is larger than the elastic constant K ₂ of the spring of the first speed regulator 3. (3) Before the engine 1 is started, the second speed regulator 4 stops the first speed regulator 3 at a predetermined position until the starting rotation speed is reached. (For example, until the rotation speed reaches 1500 rpm.)

As shown in FIG. 4 (a), since no pressure is applied to the first speed regulator and the second speed regulator, the connecting member 5 is slightly different from that shown in FIG. Is pulled to the right side of. Therefore, the governor lever 6 is in the intermediate position.

Immediately after starting (1) When the engine 1 is started, solenoid valves SV ₁ and SV ₂ are generated by a signal from an electronic device. Is energized and both circuits are energized. The negative pressure chamber of the compressor 11 becomes negative pressure when the engine starts. In addition, air is slightly sucked in through the solenoid valve SV ₂ , compressed, and accumulated in the receiver tank 13. (2) Since the hydraulic pressure gradually increases from the gear pump 11a at the rear of the compressor 11, the hydraulic pressure starts to be applied to the load reducing device 12 and the second speed regulator 4 in accordance with the increase in the hydraulic pressure. (3) When the amount of air sucked into the intake regulating valve 10 by the solenoid valve SV ₂ reaches a predetermined value, the hydraulic pressure of the compressor 11 causes the piston 12a of the load reducing device 12 to move to the elastic member 12b. It moves against elasticity, and at the same time, the valve 10a of the intake regulating valve 10 starts to open. (4) The second speed regulator 4 starts to move from the fixed starting speed position to the release position.

As shown in FIG. 4 (b), since the pressure of the second speed regulator 4 becomes large, the contact between the guide bar 9 and the long hole 8 a is separated, and the air pressure of the first speed regulator 3 causes the connecting member. 5. The position of the governor lever 6 is determined, and the governor lever 6 is positioned on the high speed side (H) for several seconds, but the air pressure is applied to the first speed regulator, so the governor lever 6 moves to the low speed side (L).

Warm-up operation (1) When the pressure in the receiver tank 13 reaches 2-3 kg / cm ² after operating for a predetermined time in the above state, the air pressure flowing through the solenoid valve SV ₁ pressurizes the diaphragm, The valve 10a is closed. At the same time, pressure is also applied to the first speed regulator 3, and the governor lever 6 of the engine 1 is moved to the low speed side via the connecting member 5 and the governor rod 2. (2) In this state, the warm-up operation of the engine 1 is continued until the set time of the electronic device.

As shown in FIG. 4 (c), since the air pressure in the first speed regulator 3 becomes 1 to 2 kg / cm ² , the guide bar 9 slides in the elongated hole 8a, and the connecting member 5, Since the governor rod 2 is pressed to the right in the drawing, the governor lever 6 is moved to the low speed side L to perform the warm-up operation.

During normal operation (1) After completion of warm-up operation, a no-load operation state is set, and the valve 10a of the intake control valve 10 opens and closes according to the air consumption on the load side from the outlet 16 of the receiver tank 13. At the same time, the first speed regulator 3 works together to move the governor lever 6 of the engine 1 from high speed to low speed. As shown in FIG. 4 (d), the air pressure of the first speed regulator 3 decreases during operation, so the guide bar 9 slides in the elongated hole 8a and the connecting member 5 moves to the left side of the drawing. Then, the governor lever 6 moves to the high speed side (H).

The control mechanism portion of the rotation control device of the present invention will be described with reference to FIG. 2. As described above, the first speed regulator 3 for adjusting the air pressure is provided by facing the mounting plate A with the two speed regulators. And a second speed regulator 4 for adjusting the hydraulic pressure are arranged, and a connecting member 5 for connecting to the governor rod 2 and an idling stopper 8 are attached to the tips of the piston rods 3a, 4a, respectively. A guide bar 9 of a connecting member 5 is slidably fitted in an elongated hole 8a of an idling stopper 8 connected to the drive regulator 4. Therefore, the piston rod 3a of the first speed regulator 3 is tracked and controlled by the guide bars 9 contacting both ends of the elongated hole 8a of the idling stopper 8, and the coupling member 5 (governor rod 2) connected to the governor lever 6 is tracked and controlled. To be done.

Relative relationship between engine speed and air pressure [Fig. 5 (a), 5 (b)] In comparison between a conventional large-sized portable compressor and the engine-driven compressor of the present invention, the engine speed and air pressure are compared. The relative relationship will be explained with reference to the time charts of [Fig. 5 (a)] and [Fig. 5 (b)]. Regarding the change of the engine speed [Fig. 5 (a)], in the conventional example (thin line), immediately after starting The speed is increased to 1700 rpm for t seconds, while the compressor equipped with the rotation control device of this invention (thick line) has a slow increase in speed immediately after starting and then a slow warm-up operation. On the other hand, regarding the pressure fluctuation in the receiver tank [Fig. 5 (b)], in the conventional example (thin line), immediately after starting, it is slightly inhaled by the intake adjustment valve 10 and balanced, resulting in low pressure (1-2 kg / cm2). ² ) In the state of warm-up On the other hand, the engine-driven compressor of the present invention (thick line) is equipped with the load reducing device 12, so immediately after starting, it is not inhaled immediately and the pressure is close to (0 kg / cm ² ). The intake regulating valve 10 is gradually opened by the movement of 12, the pressure rises in a gentle curve, and warm-up operation is performed.When the no-load pressure is reached, the compressor is in normal operation.

In the embodiment of the present invention, the discharge amount of the engine horsepower 450 ps / 1800 rpm compressor is 52 m ³ / min, but the same can be applied to a small machine. Further, in this embodiment, an example in which a gear pump is provided at the rear end of the compressor is shown, and the hydraulic pressure is used from this gear pump, but it goes without saying that it is also possible to use another system, such as engine hydraulic pressure.

[0022]

[Effect of device]

 According to this invention, the following remarkable effects are obtained. The two speed regulators are opposed to each other, one is operated by air pressure and the other is operated by hydraulic pressure, and each uses the air or hydraulic pressure of the compressor, which simplifies the configuration. Also, one speed regulator is made to follow both ends of the long hole of the idling stopper of the other speed regulator. Therefore, the idling speed can be freely set, the high speed operation can be prevented from continuing for several tens of seconds at the start, and stable and ideal warm-up operation can be performed.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an engine-driven compressor incorporating a rotation control device of the present invention.

FIG. 2 is an enlarged perspective view of a main part of the rotation control device of FIG. .

FIG. 3 is a sectional view showing the structure of a speed regulator unit according to an embodiment adopted in the present invention.

FIG. 4 is an operation explanatory view of the rotation control device of the present invention.

FIG. 5 is a timing chart showing the relative relationship between the engine speed and the receiver tank internal pressure.

[Explanation of symbols]

 1 ... Engine 2 ... Governor rod 3 ... 1st speed regulator 4 ... 2nd speed regulator 5 ... Connecting member 6 ... Governor lever 7 ... Governor 8 ... Idling stopper 9 ... Guide bar 10 ... Intake adjusting valve 11 ... Compressor 12 ... Load reducer 13 Receiver tank 14 Pressure adjustment valve 15 Manual valve

Claims (1)

[Scope of utility model registration request] 1. An engine driven compressor in which an intake air regulating valve is provided in a compressor body, and a capacity and a rotation are controlled by a first speed regulator from a receiver tank connected to the compressor via a pressure regulating valve. A second speed regulator, which is hydraulically operated facing the speed regulator, is attached to the engine block, a connecting rod with an elongated hole is arranged between these speed regulators, and the rod of the first speed regulator is attached to the elongated hole. It is loosely fitted and the connecting rod is fixedly attached to the rod of the second speed regulator to interlock with them.
The governor rod connected to the rod of the first speed regulator actuates the governor lever of the engine, and immediately after the engine is started, the second speed regulator is actuated to suppress an increase in rotation of the engine and perform warm-up operation. A rotation control device for an engine-driven compressor.