JPH0634141U - Engine starter - Google Patents

Abstract

(57) [Abstract] [Purpose] In a device for starting an internal combustion engine / external combustion engine using a DC motor 3, to shorten the starting time without increasing the capacity of the DC motor 3. [Structure] A variable resistor 5 is inserted between the battery 1 and the DC motor 3, and the resistance value of the variable resistor 5 is changed so as to be large at the beginning of start and near the end of start. It was made to change up to.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a starting device for starting an internal combustion engine or an external combustion engine by using a DC motor, and in particular, it can be effectively applied to a rotary engine such as a gas turbine that is started by a starting motor for several tens of seconds. .

[0002]

[Prior art]

 FIG. 5 shows the configuration of a conventional starting device using a DC motor. In the figure, reference numeral 1 is a battery, 2 is a switch, 3 is a DC motor, 4 is an engine such as a gas turbine.

As shown in FIG. 5, in a conventional starting device, a DC power source or battery 1, a switch 2, and a DC motor 3 are arranged in this order. Here, when the switch 2 is connected, a current flows from the battery 1 to the DC motor 3, the DC motor 3 rotates, and the engine 4 is started. When the speed of the engine 4 is increasing and the start completion point near the rated speed is reached, the DC motor 3 is disconnected and the engine 4 is made independent.

[0004]

[Problems to be solved by the device]

 In the conventional starter, the engine start time is governed by the battery capacity and the withstand voltage / current capability of the DC motor. That is, the DC motor 3 receives a rated voltage of the battery at a rated speed with a current having a full battery capacity immediately after starting. Therefore, the torque of the DC motor becomes maximum at the time of starting and becomes zero at the rating. As a result, the total torque considering the self-torque of the engine becomes slack at the intermediate speed of the engine, and the starting time of the engine is dominated by the passage time of this minimum torque.

The present invention has been made in view of the above circumstances. It is possible to shorten the starting time without increasing the capacity of the DC motor, or to reduce the capacity of the battery and the direct current motor when the starting time is the same. It is an object of the present invention to provide a starting device for an engine capable of measuring.

[0006]

[Means for Solving the Problems]

 According to the present invention, in the starting device for starting an engine using a DC motor, the resistance value between the battery and the DC motor is large at the beginning of the start and near the completion of the start. In the engine starting device, there is provided a variable resistor that changes to a minimum or zero.

[0007]

[Action]

 According to the above means, when the voltage of the battery is increased, the variable resistor reduces the current flowing to the DC motor immediately after the start to less than the motor allowable current to prevent a large current from flowing, and at the completion of the start, the DC motor Although the terminal voltage of is reduced to less than the motor withstand voltage, the torque of the DC motor can be increased at the intermediate speed after starting. The increase in torque in this intermediate speed range contributes to shortening the starting time.

[0008]

【Example】

 FIG. 1 is a block diagram showing an embodiment of an engine starting device according to the present invention. In FIG. 1, the same parts as those shown in FIG. 5 are designated by the same reference numerals, and detailed description thereof will be omitted.

According to FIG. 1, a variable resistor 5 is inserted in series between the switch 2 and the DC motor 3. The variable resistor 5 has a fixed contact at an intermediate position in the moving range of the slider, and when the engine 4 is at zero speed, the slider is at the position of maximum resistance as shown in the figure.

Here, when the switch 2 is turned on, the current from the battery 1 is determined by the variable resistor 5 and the internal resistance of the DC motor 3, and the voltage drop of the variable resistor 5 due to the current, the DC motor The terminal voltage of 3 becomes low. Therefore, when used, the battery voltage can be raised by the voltage drop. The variable resistor 5 is driven by the speed of the engine 4 to move the slider in the direction of the arrow shown, and gradually changes the resistance value toward zero. When the slider passes the position where the resistance value is 0, the resistance value of the variable resistor 5 gradually rises and changes to the maximum value at the completion of starting, that is, when the DC motor 3 is disconnected from the engine 4.

FIG. 2 compares the characteristics of the starting device according to the present invention with those of the conventional starting device. In the figure, the characteristics according to the present invention are shown by solid lines and the characteristics by conventional devices are shown by broken lines. Further, the horizontal axis represents the engine speed, point A indicates the start of starting, and point B indicates the point at which the engine is self-sustaining, that is, the point at which the starting DC motor is disconnected and the start is completed.

According to FIG. 2, the motor terminal voltage a rises immediately after the start and reaches the maximum at the time B when the start is completed. On the other hand, the motor torque b is maximum immediately after starting and becomes minimum when starting is completed. Therefore, the total engine torque c becomes minimum in the intermediate speed range.

However, in the case of the present invention, as can be seen from this figure, when the battery voltage is set high, it becomes possible to increase the voltage in the vicinity of the intermediate point. Can be made larger than the conventional one. As a result, the minimum value of the total engine torque becomes large, and as a result the starting time can be shortened.

FIG. 3 shows an example of controlling the variable resistor 5 of the starting device according to the present invention. In this figure, d represents a change in the additional resistance value added by the variable resistor 5 interposed in the current path, e represents a motor current, e ₀ represents a change in the motor current by the conventional device, and f represents Indicates the motor allowable current.

In FIG. 3, in the vicinity of the engine start start point A, the additional resistance value d gradually decreases from the point A and the motor current e rises. Especially, at the peak point d ₁ , the motor current e is the motor current e. The permissible current f is satisfied. Also, at the point d ₂ at the completion of starting, the motor terminal voltage is set to be equal to or lower than the motor allowable withstand voltage due to the additional resistance value. As a result, the motor current e remains high for a few seconds immediately after starting, a current higher than the motor current e ₀ of the conventional device flows, and the torque changes as shown in FIG.

FIG. 4 shows another control example of the variable resistor 5 of the starting device according to the present invention. In the case of this embodiment, the additional resistance value d is changed only at the beginning of the start and near the completion of the start, and is zero at the intermediate speed. As a result, the motor current e changes as shown. That is, for a few seconds immediately after starting, the resistance is interposed until the speed at which the motor rotation increases and the battery output current becomes equal to or less than the allowable current without resistance (motor current e ₁ ). After that, the operation is performed with a resistance value of zero (motor current e ₂ ). Then, the motor terminal voltage rises as the motor rotation increases, so a resistor is added again in the middle to protect the motor withstand voltage (motor current e ₃ ). In this case, it is possible to maximize the capabilities of the motor and battery, and the shortest start-up is possible by selecting the optimum combination.

The variable resistor 5 can be of a rotary type or a type of linearly moving the slider, and in either case, the rotational position or linear position of the variable resistor 5 is such that a planned resistance value corresponding to the turbine speed can be obtained. It is controlled and driven by a motor.

[0018]

[Effect of device]

 According to the present invention, by shortening the passage time at the minimum torque, it is possible to shorten the engine starting time without increasing the capacity of the DC motor, and conversely, if the starting time is the same, the battery and motor It is possible to reduce the capacity.

[Brief description of drawings]

FIG. 1 is a block diagram of a basic type showing an engine starting device according to the present invention.

FIG. 2 is an explanatory view showing characteristics of the device according to the present invention.

FIG. 3 is an explanatory diagram showing a basic control example of the device according to the present invention.

FIG. 4 is an explanatory view showing another control example of the device according to the present invention.

FIG. 5 is a configuration diagram showing a conventional starting device.

[Explanation of symbols]

 1 Battery 2 Switch 3 DC Motor 4 Engine 5 Variable Resistor

Claims (1)

[Scope of utility model registration request] 1. A starting device for starting an engine using a DC motor, wherein a resistance value between a battery and the DC motor is large at the beginning and near the completion of the starting, and becomes minimum or zero at an intermediate starting speed. A starting device for an engine, comprising a variable resistor that changes.