JPH0624665Y2 - Gas amount control valve - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrically operated gas amount control valve, and when a needle valve constituting the valve is fully opened or fully throttled, The contact portion, such as the valve hole, which opposes this is prevented from impacting, and the durability of the gas amount adjusting valve is improved. 2. Description of the Related Art Among gas appliances, in appliances such as so-called table stoves, ignition and fire extinguishing operations are frequently performed, and heat power is frequently adjusted while the appliances are in use. In a conventional appliance, a so-called gas cock is adopted as a gas amount adjusting device for heat power adjustment.
By rotating the operation knob, it is possible to adjust the valve opening degree to a desired value, and thereby the heat power can be adjusted arbitrarily. However, in this gas amount adjusting device, the operating torque is large and it is necessary to set the operating knob to a certain size. For this reason, the gas stove has a problem that the operating knobs for ignition, extinguishing, and adjusting the heat power are large. As a means for solving such a problem, it is possible to adopt an electric valve, and for example, the configuration of FIG. 3 can be adopted. As shown in the figure, this one uses a reversible rotation type electric motor (M) output shaft to move a needle valve (N) of a gas amount regulating valve (1) to a corresponding valve hole (21). The shaft portion (11) of the needle valve (N) is screw-paired with the constituent wall of the main body (2) so as to enable the contact and separation operation. A T-shaped leak hole (10) is formed at the tip of the needle valve (N), and even if the needle valve (N) abuts the valve hole (21), the gas burner ( A certain amount of gas can be supplied to B). In this device, when one of the valve opening operation switches (31) is closed, the electric motor (M) is normally rotated for the closing time, and the needle valve (N) is moved away from the valve hole (21). However, the gas flow rate is increased.
On the contrary, when the other aperture control switch (32) is closed,
During this closing time, the electric motor (M) reversely rotates, the needle valve (N) moves closer to the valve hole (21), and the gas amount is throttled. In the case of such a configuration, the operation switches (3
1) Since the amount of gas can be adjusted by the operation of (32),
In addition to the advantage that the operation force is light, the configuration of the operation unit becomes compact because only the operation switch is arranged on the operation surface of the instrument. However, the gas amount adjusting valve (1) of the above type is used.
In the gas appliance incorporating the above, when the needle valve (N) reaches the most throttled state, the needle valve (N) impacts the valve hole (21) and stops, and the needle valve (N N) and the valve hole (21) are easily damaged. When the needle valve (N) reaches the fully opened state by operating the valve opening operation switch (31), the needle valve (N) impacts the constituent wall of the gas amount adjusting valve (1), the stopper of the drive mechanism, and the like. Therefore, even in this case, there is a problem that the needle valve (N) is easily damaged. The present invention has been made in view of the above-mentioned points. "The electric motor (M) driven by the operation switch and the electric motor (M) are brought into contact with and separated from the valve hole (21). In a gas amount control valve (1) having a needle valve (N), when the needle valve (N) moves to the end of the opening / closing operation range such as the maximum throttle position, the needle valve (N) has a valve hole. It is an object of the present invention to reduce the damage of the contact portion such as (21) so as not to collide with the contact portion by shock so as to improve the durability of the gas amount regulating valve. The technical means of the present invention for solving the above-mentioned problems are as follows: "The potentiometer (P) for detecting the moving amount of the needle valve (N) and the end of the opening / closing operation range of the needle valve (N). Reference value holding means (30) storing the same signal as the signal output from the potentiometer (P) when it reaches the vicinity of the part
And a movement amount comparison means (39) for comparing the movement amount of the needle valve (N) indicated by the output signal of the potentiometer (P) with the reference value holding means (30) and outputting a deceleration signal when the latter becomes large. ) Is provided, and when the movement amount comparing means (39) outputs a deceleration signal, the current supplied to the electric motor (M) is limited to decelerate the electric current. The above technical means operates as follows. When the operation switch is operated to drive the electric motor (M), the needle valve (N) is opened and closed in conjunction with the electric motor (M), and the needle valve ( The movement amount of N) is detected by the potentiometer (P). Reference value holding means for storing the same signal as the signal detected by the potentiometer (P) when the needle valve (N) reaches the vicinity of the end of the opening / closing operation range (fully opened or the vicinity of the maximum throttle position). The output of (30) and the actual output of the potentiometer (P) are compared by the movement amount comparison means (39), whereby the movement amount of the needle valve (N) is set in the reference value holding means (30). It is monitored whether the value is not exceeded. Eventually, when the needle valve (N) further moves beyond the vicinity of the end of its moving range, the signal of the potentiometer (P) for detecting this moving amount is set in the reference value holding means (30). It becomes larger than a certain movement amount signal, and as a result, movement amount comparison means (3
The deceleration signal is output from 9). After that, the deceleration signal from the movement amount comparison means (39) causes the electric motor (M) to decelerate and rotate, and the needle valve (N) interlocked with this also has a valve hole (21) and a gas amount adjusting valve (1). It collides at low speed with the abutting portion of the constituent wall of the above, and thereby the needle valve (N) is in the fully throttled state or the fully opened state. The present invention has the following unique effects. Since the needle valve (N), which is fully opened or moved to the maximum throttle position, comes into contact with the valve hole (21) or the like at a low speed, the needle valve (N) is less damaged and the durability of the flow rate adjusting valve is improved. Embodiments of the present invention described above will now be described with reference to the drawings. As shown in FIG. 1, in the gas circuit formed in the gas amount regulating valve (1), a needle valve (N) is provided as in the conventional one, and the needle valve (N) is provided. The cam body (14) and the cam body (14) are integrally connected so as to be able to move back and forth.
In addition, the cam body (14) is coupled to the electric motor (M) through a speed reducing mechanism (K) including a large number of gears, and the downstream side of the gas inlet (22) and the upstream side of the hole (23). A solenoid valve (41) is inserted in the. The cam body (14) is housed in a cam chamber (24) formed in the upper part of the main body (2), and a screw pair between the cam body (14) and the side wall of the cam chamber (24) is provided. In order to realize this, the cam body (14) is formed into a cylindrical body, and a spiral groove portion (15) which is open to the outer peripheral side is formed in the body portion thereof. Further, the tip of a pin (16) implanted at a specific point on the side wall of the cam chamber (24) is fitted into the groove (15), whereby when the cam body (14) rotates, the groove (15) of the groove (15) moves. The needle valve (N) linearly moves according to the degree of inclination. Next, a head portion (18) formed at the upper end of the shaft portion (11) is connected to the lower portion of the cam body (14) in a rotating and paired state. In the middle, the O-ring (12) is attached to maintain the airtightness of the sliding part with the hole (23). Further, the needle valve (N) is a conical valve body formed at the tip of the shaft portion (11), and a continuous portion with the shaft portion (11) has a small diameter portion having a hole opening in the radial direction. Has become
A leak hole (10) communicating with the hole is formed coaxially with the needle valve (N). Therefore, even when the needle valve (N) is in contact with the valve hole (21), the gas inlet (22) and the gas outlet (25) are not connected to the leak hole (1).
0), so that a constant amount of gas can be secured at the time of maximum throttle. Further, the gas amount adjusting valve (1) is used by connecting a gas burner (B) on the downstream side as shown in FIG. Next, the control circuit of the gas amount adjusting valve (1) will be described. As shown in FIG. 2, the electric motor (M) is set to be reversibly operated by two operation switches (31) and (32), and these operation switches (31) and (32) are used. Uses a push-button switch. These operation switches (31) (32) are connected to a drive circuit of an electric motor (M), and this drive circuit is composed of an opening drive circuit (U) and a diaphragm drive circuit (D), and a valve opening operation switch. When (31) is closed, electric current in the forward direction is supplied to the electric motor (M) through the opening drive circuit (U), the opening of the needle valve (N) increases, and conversely, the throttle operation switch ( When 32) is closed, current in the reverse rotation direction is supplied via the diaphragm drive circuit (D). The output shaft of the reduction mechanism (K) driven by the electric motor (M) has a potentiometer (P).
Are configured to interlock with each other, and the output value from the potentiometer (P) changes according to the rotation angle of the output shaft, that is, the cam body (14). This output value is given as a voltage change, and when the opening of the needle valve (N) reaches the maximum opening, the output value of the maximum voltage level is output. The output value of the voltage level is output. The output of the potentiometer (P) indirectly detects the opening of the needle valve (N).
A first comparison circuit (3) which constitutes a movement amount comparison means (39).
3) and the second comparison circuit (34). The first and second comparison circuits (33) and (34) are provided at the time when the opening of the needle valve (N) reaches a predetermined opening near the fully open position (hereinafter referred to as the first set opening) and the maximum throttle position. The time when a predetermined opening degree (hereinafter referred to as a second set opening degree) in the vicinity of (a state where the needle valve (N) is in contact with the valve hole (21)) is detected. The output of the first resistor (35) and the output of the potentiometer (P) are set to the first comparison circuit (33), and the other second comparison circuit (34) receives the second set opening degree. The output of the second resistor (36) and the output of the potentiometer (P) for setting are applied. Further, in this embodiment, the first resistor (35) and the second resistor (36) correspond to the reference value holding means (30) described in the above-mentioned technical means, and
The first comparison circuit (33) and the second comparison circuit (34) correspond to the movement amount comparison means (39) described in the technical means section. The output of the first comparison circuit (33) is a first for dividing the current of the opening drive circuit (U) connected to the electric motor (M) via the valve opening operation switch (31) at a predetermined timing. The output of the second comparison circuit (34), which is applied to the base of the first transistor (T1) inserted in the shunt circuit (37), is supplied to the electric motor (M) via the throttle operation switch (32). ) Is applied to the base of the second transistor (T2) inserted in the second shunt circuit operation switch for shunting the current of the diaphragm drive circuit (D) connected to (4). Due to the above-mentioned configuration, in this embodiment, the opening degree of the needle valve (N) is increased by operating the valve opening operation switch (31) so that the opening degree is the first.
When the set opening is reached, the output from the first comparison circuit (33) causes the first transistor (T1) to conduct, and the current applied to the electric motor (M) is shunted through the first shunt circuit (37). . As a result, after this point, the electric motor (M)
The electric current applied to the electric motor (M) decreases, the rotational torque of the electric motor (M) decreases, and the opening speed of the needle valve (N) decreases. On the contrary, when closing the opening of the needle valve (N) by closing the opening switch (32), when the opening reaches the second set opening, the second comparison circuit (34) outputs the second opening.
The transistor (T2) becomes conductive, and the current applied to the electric motor (M) is shunted through the second transistor (T2).
The rotation torque of the needle valve (N) decreases and the throttle speed of the needle valve (N) decreases. As described above, in this embodiment, the needle valve (N) changes its opening degree from the first set opening degree in the vicinity of full opening to the full opening direction, and the throttle change from the vicinity of the maximum throttle position to the direction of the maximum throttle position. At this time, the moving force of the needle valve (N) becomes low, and the moving speed becomes lower than the opening change speed in other regions. Therefore, even when the needle valve (N) comes into contact with the valve hole (21), the impact force at the time of this contact is small and problems such as damage to the valve body can be alleviated. Further, even when the rotation of the electric motor (M) is blocked in the maximum throttle state, the current flowing through the electric motor (M) is small, so that the inconvenience of damaging the excessive current flowing through the motor coil is reduced. . This advantage is also applicable to the case where the fully open position of the needle valve (N) is set by mechanical contact with the wall surface or the like of the gas amount adjusting valve (1). Next, in this embodiment, a maximum opening setting device (5) is added, and when the valve opening operation switch (31) is closed and the needle valve (N) is opened, When the needle valve (N) is fully opened, the maximum opening degree setting device (5) cuts off the electric power supply to the electric motor (M). The device will be described in more detail below. As a configuration for setting the fully open position of the needle valve (N), a third comparison circuit (51) is adopted, and the output from the potentiometer (P) is applied to the third comparison circuit (51). The output of the third resistor (53) that sets the comparison voltage to a predetermined value is applied. The voltage of the third resistor (53) is set to match the voltage applied when the needle valve (N) is in the fully open state. The output from the third comparison circuit (51) is input to the switch circuit (55), and the switch circuit (5)
5) includes a normally-closed output contact (57) corresponding to a reset input after a predetermined signal is input, until the reset input.
To maintain the closed state. With the above configuration, when the opening degree of the needle valve (N) reaches full opening, the output from the third comparison circuit (51) is generated, the normally closed output contact (57) is opened, and the circuit of the electric motor (M) is opened. Is cut off and the electric motor (M) is stopped. FIG. 2 shows an electric circuit when the present invention is applied to a gas appliance. One of the contacts (40b) of the main switch (40) and the valve opening in the open drive circuit (U). The downstream side of the operation switch (31) and the circuit of the potentiometer (P) are connected, and the main switch (4)
The other contact (40a) of 0) is inserted in the ground circuit from the electric motor (M). Therefore, when the main switch (40) is brought into the instrument stop state (state shown by the solid line in FIG. 2), the contact (40b) of this switch is closed, and the electric motor (M) and the maximum opening setting device ( 5), electricity is supplied to the gas amount adjusting valve (1), its opening is increased, and when the needle valve (N) is fully opened, the switch circuit (55) is activated by the output from the third comparing circuit (51). Then, the normally-closed output contact (57) is opened, and the device is stopped. This allows the main switch (4
When 0) is operated to reignite the appliance, a certain amount of gas will flow out from the gas burner (B) on the downstream side, and ignition failure is unlikely to occur. At the time of ignition, the main switch (40) is connected to the contact (40a) side to operate the ignition device (6) and the solenoid valve (41) is opened, whereby the downstream gas burner (B) burns. Will be done. Further, (42) in the figure is a power switch.

[Brief description of drawings] FIG. 1 is a sectional view of an embodiment of the present invention. FIG. 2 is a circuit diagram of an embodiment of the present invention. FIG. 3 is an explanatory diagram of a conventional example. [Explanation of sign] (21) ・ ・ ・ Valve hole (30) ... Reference value holding means (M): Electric meter

Claims (1)

[Claims for utility model registration] Gas amount adjustment including an electric motor (M) driven by an operation switch and a needle valve (N) operated by the electric motor (M) to move toward and away from a valve hole (21) Needle valve (N) in valve (1)
Of the potentiometer (P) for detecting the amount of movement of the needle valve and the reference value holding means for storing the same signal as the signal output by the potentiometer (P) when the needle valve (N) reaches the vicinity of the end of the opening / closing operation range ( 30) and the reference value holding means (3
0) and the movement amount of the needle valve (N) indicated by the output signal of the potentiometer (P) are compared, and a movement amount comparison means (39) for outputting a deceleration signal when the latter becomes large is provided.
A gas amount adjusting valve for limiting the current supplied to the electric motor (M) to decelerate the electric current when the movement amount comparing means (39) outputs a deceleration signal.