JPH037555Y2 - - Google Patents

Description

[Detailed description of the invention] Among engine working machines, this invention is particularly an engine generator equipped with a generator as a working machine, specifically, an engine and a generator driven by the engine are interlocked and connected, and the engine generator is equipped with a generator as a working machine. a load detection device that detects the load;
The present invention relates to an engine generator including a control device that controls the operating state of the engine based on the detection result of the load detection device.

Conventionally, this type of engine generator has been equipped with a rotation speed control means that increases or decreases the engine rotation speed stepwise or steplessly in response to the load condition detected by the load detection device. be. However, with this conventional system, the idling speed must be set higher than the voltage rise speed in preparation for sudden switching from no load to loaded, which reduces fuel consumption and noise generation. There are significant restrictions on. Moreover,
When the engine speed is increased or decreased in response to the light or heavy load, the voltage and frequency of the output current fluctuate, which poses a problem that adversely affects welding work and the like. Furthermore, when the rotational speed is reduced, the average effective pressure of the engine decreases, resulting in poor fuel efficiency and an increase in harmful components in the exhaust gas.

In view of these circumstances, the present invention maintains the engine speed at a predetermined rated speed under load, stabilizes the output current, improves fuel efficiency, and reduces harmful components in the exhaust. The purpose is to further save fuel consumption and reduce noise generation during no-load conditions.

In order to achieve this objective, the present invention provides a high load signal when the load detection device detects a high load of the generator that is above a predetermined value, and a low load signal when it detects a low load that is below the predetermined value. The control device is configured to output a no-load signal when detecting a no-load condition, and the control device has a rotation speed control means and an operating cylinder number control means, and the rotation speed control means outputs a no-load signal when detecting a high load of the load detection device. The engine speed is controlled at a constant speed to a rated speed based on either the signal or the low load signal, and the engine speed is controlled to a constant speed at an idling speed based on a no-load signal from the load detection device. The operating cylinder number control means operates all cylinders of the engine based on the high load signal from the load detection device, and reduces the number of operating cylinders of the engine based on either the low load signal or the no-load signal from the load detection device. It is characterized by being configured to allow

Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a block diagram showing the concept of an embodiment of the present invention, FIG. 2 is a flowchart showing the operation of the control device, FIG. 3 is a cross-sectional plan view thereof, and FIG.
The figure is a longitudinal side view.

This engine generator is an engine generator to which load sources La to Ln consisting of a plurality of welding torches are electrically connected and used as a power source for welding machines such as welding torches. A generator 3 that is coupled and electrically connected to a welding machine, a load detection device 4 that detects the load state of the generator 3, and an operating state of the engine 2 is controlled based on the detection result of the load detection device 4. control device 5
Equipped with.

The load detection device 4 detects the load based on the output current of the generator 3, and when it detects that the load of the generator 3 is a high load exceeding a predetermined value, it outputs a high load signal to the portion below the predetermined value. It is configured to output a low load signal when detecting a load, and output a no-load signal when detecting no load.

The control device 5 includes a rotation speed control means 6 and an operating cylinder number control means 7. The rotation speed control means 6 controls the rotation speed of the engine 2 when receiving a high load signal or a low load signal from the load detection device 4. It is configured to perform constant speed control to the rated rotation speed, and to perform constant speed control to the no-load idling rotation speed when a no-load signal is input from the load detection device 4. The operating cylinder number control means 7 operates all cylinders of the engine 2 when a high load signal is input from the load detection device 4, and operates some cylinders of the engine 2 when a low load signal or a no-load signal is input. The engine 2 is configured to stop the fuel supply and cause the engine 2 to perform reduced-cylinder operation.

In addition, numeral 8 is a soundproof case, 9a and 9b are cooling air ducts, 10 is a cooling air intake, 11 is a cooling air inlet, 12 is a radiator with a fan, 13 is an air cleaner, 14 is an exhaust manifold, 15 is a fuel tank, 16 each indicates a machine room. From the cooling air inlet 11 of the cooling air ducts 9a and 9b to the machine room 1
The air flowing into the work equipment 3 and the air cleaner 1
3. Since the cooling air ducts 9a, 9b, the cooling air intake 10, and the cooling air inlet 11 are arranged so as to flow toward the exhaust manifold 14 and the control device 5, the working equipment 3, etc. is cooled to

Next, the operation of this engine generator will be explained based on FIG. 2, with particular emphasis on the operation of the control device 5.

When loads from more than half of the load sources La to Ln electrically connected to the engine generator are acting on the generator 3, the load detection device 4 outputs a high load signal, and the control device receives the high load signal. The rotational speed control means 6 of 5 rotates the engine 2 at a rated rotational speed of, for example, 3600 rpm. At the same time, the operating cylinder number control means 7 which receives the high load signal causes the engine 2 to operate with all cylinders.

For example, when loads from less than half of the load sources La to Ln act on the generator 3 of the engine generator, the load detection device 4 outputs a low load signal. The rotation speed control means 6 to which this low load signal is input operates the engine 2 at the rated rotation speed in the same way as when inputting the high load signal. However, the operating cylinder number control means 7
This is different from when a high load signal is input.
-225372 etc., the number of times fuel is supplied to each cylinder of engine 2 is reduced by half,
Make engine 2 perform 50% reduced cylinder operation.

Furthermore, when the load on the generator 3 of the engine generator disappears, the load detection device 4 outputs a no-load signal. When the rotational speed control means 6 receives this no-load signal, it controls the engine rotational speed to the no-load idling rotational speed, unlike when a high-load signal or a low-load signal is input. The operating cylinder number control means 7 can reduce the number of operating cylinders of the engine 2 by 50% in the same way as when outputting the low load signal.

FIG. 5 is a block diagram conceptually showing another embodiment of the present invention. In this embodiment, the load detection device 4 includes a load detection device 41 that does not perform no-load detection, and a no-load detection device 42 that performs no-load detection. The load detection device 41 is configured to detect the load on the engine 2, and the no-load detection device 42 is configured to detect the load on the work machine 3. The other configurations are the same as the previous example, and the same effects as the previous example can be obtained.

Note that this cylinder reduction operation of the engine 2 may be performed by stopping the operation of a specific cylinder among multiple cylinders, but by stopping all cylinders in sequence, the heat load of each cylinder of the engine 2 can be averaged. It is desirable that the

In addition, in this example, the cylinder reduction operation is limited to 50% cylinder reduction, but in addition, depending on the size of the load, for example, 2/3 cylinders are stopped for partial loads of 1/3 or less. /3 cylinder reduction, and for loads from 1/3 to 2/3, 1/3 cylinders are stopped, and for loads over 2/3, all cylinders are operated. You can also do this.

Further, in this example, an engine generator used as a power source for a welding machine has been described, but an engine generator used as another power source may be used.

Furthermore, in the case of an engine generator whose rotational speed can be lowered to idling speed, no-load in the present invention is not simply no-load in a physical sense, but also a small partial load that can be equated with this. It is also used in a meaning that includes. In such engine generators, the load detection device is configured to output a no-load signal not only when detecting a complete no-load but also when detecting a small partial load close to it, and the control system receives the no-load signal. The control device can be configured so that the device operates the engine at a no-load idling speed with reduced cylinders, or outputs a minimum load signal when the above-mentioned small partial load is present, and a complete no-load signal when there is a complete no-load. When receiving a complete no-load signal than when receiving a minimal load signal, the engine generator is further controlled at a constant speed to a low-speed idling rotation that is lower than the no-load idling rotation speed. The control device can be configured to allow.

As explained above, in the engine generator according to the present invention, when the load detection device detects a high load of the generator equal to or higher than a predetermined value, the load detection device outputs a high load signal.
The control device is configured to output a low load signal when detecting a low load below the predetermined value, and output a no load signal when detecting no load, and the control device includes a rotation speed control means and an operating cylinder number control means. The rotation speed control means constant-speed controls the engine rotation speed to the rated rotation speed based on either the high load signal or the low load signal from the load detection device, and controls the engine rotation speed to a constant speed based on the no-load signal from the load detection device. The number of operating cylinders is configured to control the rotational speed at a constant speed to an idling rotational speed, and the operating cylinder number control means operates all cylinders of the engine based on the high load signal from the load detection device, and operates the engine based on the low load signal and no load signal from the load detection device. This system is configured to reduce the number of operating cylinders of the engine based on either of the above, and when under load, the engine output corresponding to the light or heavy load can be obtained by operating the engine with fewer cylinders without reducing the engine speed. This stabilizes the voltage and frequency of the output current, and also maintains the average effective pressure of the engine at a high level, resulting in fuel savings.

In addition, when there is no load, the engine speed is reduced to the no-load idling speed while operating with reduced cylinders, which further saves fuel and reduces noise generation.

[Brief explanation of the drawing]

Fig. 1 is a block diagram conceptually showing an embodiment of the present invention, Fig. 2 is a flowchart showing the operation of the control device, Fig. 3 is a cross-sectional plan view thereof, and Fig. 4 is a longitudinal cross-sectional side view thereof. FIG. 5 is a block diagram conceptually showing another embodiment of the present invention. 2... Engine, 3... Generator, 4... Load detection device, 5... Control device, 6... Rotation speed control means, 7... Operation cylinder number control means.

Claims (1)

[Claims for Utility Model Registration] The engine 2 and the generator 3 driven by the engine 2 are interlocked and connected, and the load detection device 4 detects the load on the generator 3. Based on the detection result of the load detection device 4, the engine In the engine generator, the load detection device 4 outputs a high load signal when the load of the generator 3 detects a high load of more than a predetermined value, and outputs a high load signal when the load of the generator 3 detects a low load of less than the predetermined value. The control device 5 is configured to output a low load signal when detecting a low load, and output a no load signal when detecting a no load, and the control device 5 has a rotation speed control means 6 and an operating cylinder number control means 7, The control means 6 controls the engine 2 based on either the high load signal or the low load signal of the load detection device 4.
The number of operating cylinders controlling means 7 is configured to constant-speed control the rotation speed of the engine 2 to the rated rotation speed, and constant-speed control the rotation speed of the engine 2 to the idling speed based on the no-load signal of the load detection device 4. All cylinders of the engine 2 are operated based on the high load signal of the detection device 4,
An engine generator characterized in that the number of operating cylinders of an engine 2 is reduced based on either a low load signal or a no-load signal from a load detection device 4.