Circuit device for preventing air pump of current collection trolley from being burnt

Abstract

The utility model discloses a circuit device for preventing an air pump of a current collection trolley from being burnt. The circuit device comprises an air pump motor M and a control circuit, wherein the air pump motor M is controlled by a circuit breaker QF and a contactor KM; in the control circuit, a pressure switch is connected in series with an intermediate relay to control two normally open contacts KA5; a normally open contact KA5 is connected in series with a time relay KT; the lower end of the KT contact is connected in series with four normally-closed limit switches, and a bypass switch S5 is connected in parallel with the four normally-closed limit switches and then connected in series with a KM coil; the other normally open contact KA5 is connected in series with a coil of a time relay KT; switches for unlocking, locking, extending and retracting the current collection trolley are respectively connected with an intermediate relay and form electrical interlocking; normally open contacts controlled by the corresponding intermediate relays control coils of the electromagnetic valves respectively, and needed functions are achieved. The circuit device can effectively prevent the current collection trolley air pump from being burnt down, saves materials and maintenance cost, improves production efficiency and is suitable for the port yard bridge current collection trolley air pump.

Description

Technical Field

[0001] The invention relates to a current collecting trolley used in a port yard bridge, and more specifically to a control circuit of an air pump in the current collecting trolley. Background Art

[0002] The collector trolley is a device for obtaining electricity equipped on the port yard bridge (tire crane). Each collector trolley is equipped with an air pump and is used in the port yard bridge. It is a device for the yard bridge to access the mains power, such as the collector trolley (model: 09-M190-0019P) produced by the existing technology manufacturer Kangwen Mobile Power Supply Equipment (Shanghai) Co., Ltd. The collector trolley obtains the mains power when it is extended and hung in the mains power rack, and disconnects the mains power when the collector trolley withdraws from the mains power rack and retracts. Since the collector trolley is connected to an external pneumatic lock, it is necessary to open the pneumatic lock first and then extend it to obtain the mains power; when the collector trolley is retracted, it is necessary to open the pneumatic lock first and then retract it. The "unlocking" and "locking" in the following content refer to opening and closing the pneumatic lock connected to the collector trolley, and "extending" and "retracting" refer to the extension and retraction actions of the collector trolley itself. All unlocking, locking, extending, retracting and other actions of the collector trolley are provided with air power by the air pump.

[0003] The collector trolley relies on the air pump to provide gas power to activate related mechanisms, thereby realizing the opening, locking, extension and retraction functions. The air pump contains a pressure switch. When the pressure switch detects the low pressure threshold, the air pump starts working; when the pressure switch detects the high pressure threshold, the air pump stops working. However, in practice, the on and off of the air pump are only triggered by the pressure switch. If there is a leak in the air pump, the pressure switch will misjudge, causing the air pump to keep compressing air to work, and finally causing the air pump to burn out. Summary of the invention

[0004] In view of the above problems, the present invention designs a circuit device to increase the triggering conditions for turning the air pump on and off, and uses a limit switch, a bypass switch and a time relay for comprehensive triggering, thereby reducing the working time of the air pump and preventing it from burning out.

[0005] In order to achieve the above object, the present invention provides a circuit device for preventing the air pump of a current collecting trolley from burning, comprising an air pump motor M and a control circuit controlled by a circuit breaker QF powered by a single-phase 220V; the circuit breaker QF connects the contactor KM for starting the air pump motor M and starting the control circuit; the control circuit comprises:

[0006] A pressure switch P is used to detect the current gas pressure value of the air pump; the pressure switch P is connected in series with an intermediate relay KA5 to control two normally open contacts KA5;

[0007] A normally open contact KA5 is connected in series with a time relay KT, which is a normally closed delayed disconnection contact. The lower end of the KT contact is connected in series with normally closed limit switches LS1-LS4, and the switches LS1-LS4 are respectively: unlocking limit switch, locking limit switch, extending limit switch and retracting limit switch; another bypass switch S5 is connected in parallel with the switches LS1-LS4, and then connected in series with the KM coil after parallel connection;

[0008] A normally open contact KA5 is connected in series with the coil of the time relay KT;

[0009] The collector trolley unlocking switch S1, the collector trolley locking switch S2, the collector trolley extension switch S3, and the collector trolley retraction switch S4 are respectively connected to the intermediate relay KA1, the intermediate relay KA2, the intermediate relay KA3, and the intermediate relay KA4 to form four branches; among which, the branches where the intermediate relays KA1 and KA2 are located are respectively connected in series with the normally closed contacts of KA2 and KA1 to complete the electrical interlocking; the branches where the intermediate relays KA3 and KA4 are located are respectively connected in series with the normally closed contacts of KA4 and KA3 to complete the electrical interlocking;

[0010] The normally open contacts KA1~KA4 controlled by the intermediate relays KA1, KA2, KA3 and KA4 respectively control the solenoid valve coils C1~C4 in series, forming four branches; among them, the intermediate relay KA1 is the intermediate relay controlling the unlocking solenoid valve coil C1, the intermediate relay KA2 is the intermediate relay controlling the locking solenoid valve coil C2, the intermediate relay KA3 is the intermediate relay controlling the extending solenoid valve coil C3, and the intermediate relay KA4 is the intermediate relay controlling the retracting solenoid valve coil C4.

[0011] Among them, the collector trolley unlocking switch S1, the collector trolley locking switch S2, the collector trolley extending switch S3, the collector trolley retracting switch S4, and the bypass switch S5 are manual switches.

[0012] The circuit device of the present invention can effectively prevent the air pump of the current collecting trolley from burning out, save materials and maintenance costs, and improve production efficiency, and is suitable for the air pump of the current collecting trolley of the port yard bridge. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The invention discloses a circuit diagram of a device for preventing the air pump of a current collecting vehicle from burning out. DETAILED DESCRIPTION

[0014] The external circuit of the collector trolley includes a circuit breaker QF, which is used to open and close the single-phase circuit of the air pump; a contactor KM, which is used to start and stop the air pump motor; an air pump (including an air pump motor M and a pressure relay P), M is used to compress the air and provide air power to make the collector trolley move, and P is used to detect the current gas pressure value of the air pump; S1, S2, S3, and S4 are respectively the switches for unlocking, locking, extending, and retracting the collector trolley, which can be manually operated; KA1 is the intermediate relay for controlling the unlocking solenoid valve coil, KA2 is the intermediate relay for controlling the locking solenoid valve coil, KA3 is the intermediate relay for controlling the extending solenoid valve coil, and KA4 is the intermediate relay for controlling the retracting solenoid valve coil. C1, C2, C3, and C4 are respectively the unlocking, locking, extending, and retracting solenoid valve coils, which are used to control the pneumatic lock to complete the corresponding actions. LS1-LS4 are respectively: unlock limit switch, lock limit unlock, extension limit switch and retraction limit switch, which are used to detect whether each action of the collector trolley is completed.

[0015] The present invention designs the circuit of four limit switches LS1-LS4 so that it can control the KM coil on and off, and adds an intermediate relay KA5 to control the time relay KT, which can perform timing when the pressure relay does not detect the high-voltage threshold; S5 is added as a bypass switch, and its function is that when any limit switch of LS1-LS4 is disconnected, the S5 switch can be manually opened to energize the KM coil. The control device of the present invention is described in detail below.

[0016] This circuit device adopts single-phase 220V power supply and includes the following parts:

[0017] (1) Main circuit: QF is a circuit breaker, the lower end of QF is connected to the contactor KM, KM is a contactor for starting the air pump motor, and M is the air pump motor;

[0018] (2) Control loop:

[0019] 1) Branches 1 to 4: S1, S2, S3, and S4 are switches for unlocking, locking, extending, and retracting the collector trolley, respectively. Each branch where the switch is located is connected to an intermediate relay, namely KA1, KA2, KA3, and KA4. The branches where KA1 and KA2 are located are connected in series with the normally closed contacts of KA2 and KA1, respectively, to complete electrical interlocking; the branches where KA3 and KA4 are located are connected in series with the normally closed contacts of KA4 and KA3, respectively, to complete electrical interlocking;

[0020] 2) Branches 5 to 8: Normally open contacts KA1-KA4 control solenoid valve coils C1-C4 respectively

[0021] 3) Branches 9 to 11: The 9th branch is a pressure relay P with an intermediate relay KA5 connected in series at the lower end; the 10th branch is: the normally open contact KA5 is connected in series with the normally closed delayed disconnection contact of the time relay KT, and the lower end of the KT contact is connected in series with the normally closed limit switches LS1-LS4 (LS1-LS4 are respectively: unlock limit switch, lock limit unlock, extend limit switch and retract limit switch), and there is a bypass switch S5 connected in parallel with LS1-LS4, which is then connected in series with the KM coil; Branch 11: the normally open contact KA5 is connected in series with the time relay KT coil.

[0022] The working process of the present invention is as follows:

[0023] QF is usually in a closed state, and the pressure relay P (pressure switch) detects the current gas pressure value. The low pressure threshold is set to P1, the high pressure threshold is set to P2, and the current gas pressure value of the air pump is Px. When Px≤P1, the pressure relay P is in a closed state, the KA5 coil is energized, the KA5 normally open contact is closed, the KM coil is energized, the KM normally open contact in the main circuit is closed, and the air pump motor M starts working; when Px=P2, the pressure relay P becomes disconnected, the KA5 coil loses power, the KA5 normally open contact is disconnected, the KM coil loses power, the KM normally open contact in the main circuit is disconnected, and the air pump motor M stops working.

[0024] When P1 < Px < P2, open S1. The coil of KA1 is energized, and its normally open contact KA1 closes. The solenoid valve coil C1 is energized, and the collector trolley performs the unlocking operation until the unlocking is completed. The limit switch LS1 operates and becomes a normally open contact. At this time, the coil of KM is de-energized, and the air pump motor M stops working. If you want the air pump motor M to work again, you need to open the bypass switch S5 or wait for the unlocking mechanism to naturally relieve pressure and LS1 automatically returns to the closed state; open S2. The coil of KA2 is energized, and its normally open contact KA2 closes. The solenoid valve coil C2 is energized, and the collector trolley performs the locking operation until the locking is completed. The limit switch LS2 operates and becomes a normally open contact. At this time, the coil of KM is de-energized, and the air pump motor M stops working. If you want the air pump motor M to work again, you need to open the bypass switch S5 or wait for the locking mechanism to naturally relieve pressure and LS2 automatically returns to the closed state; open S3. The coil of KA3 is energized, and its normally open contact KA3 closes. The solenoid valve coil C3 is energized, and the collector trolley performs the extending operation until the extension is completed. The limit switch LS3 operates and becomes a normally open contact. At this time, the coil of KM is de-energized, and the air pump motor M stops working. If you want the air pump motor M to work again, you need to open the bypass switch S5 or wait for the extending mechanism to naturally relieve pressure and LS3 automatically returns to the closed state; open S4. The coil of KA4 is energized, and its normally open contact KA4 closes. The solenoid valve coil C4 is energized, and the collector trolley performs the retracting operation until the retraction is completed. The limit switch LS4 operates and becomes a normally open contact. At this time, the coil of KM is de-energized, and the air pump motor M stops working. If you want the air pump motor M to work again, you need to open the bypass switch S5 or wait for the retracting mechanism to naturally relieve pressure and LS4 automatically returns to the closed state.

[0025] When P1 < Px < P2, if no operation is performed on S1 - S4, that is, when the air pump is working, the normally open contact of KA5 closes, the coil of the time relay KT is energized and starts timing. The set time of the time relay is t. Starting from the energization of the KT coil, when the time reaches t, the contact of KT disconnects, the coil of KM is de-energized, the contact of KM in the main circuit disconnects, and the air pump stops working.

[0026] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A circuit device for preventing the air pump of a current collecting vehicle from burning out, characterized in that: It includes a single-phase 220V power supply and an air pump motor M and a control circuit controlled by a circuit breaker QF; Circuit breaker QF connects the air pump motor starter M and the control circuit starter contactor KM; the control circuit includes: A pressure switch P is used to detect the current gas pressure value of the air pump; the pressure switch P is connected in series with an intermediate relay KA5 to control two normally open contacts KA5; A normally open contact KA5 is connected in series with a time relay KT, which is a normally closed delayed disconnection contact. The lower end of the KT contact is connected in series with normally closed limit switches LS1-LS4, and the switches LS1-LS4 are respectively: unlocking limit switch, locking limit switch, extending limit switch and retracting limit switch; another bypass switch S5 is connected in parallel with the switches LS1-LS4, and then connected in series with the KM coil after parallel connection; A normally open contact KA5 is connected in series with the coil of the time relay KT; The collector trolley unlocking switch S1, the collector trolley locking switch S2, the collector trolley extension switch S3, and the collector trolley retraction switch S4 are respectively connected to the intermediate relay KA1, the intermediate relay KA2, the intermediate relay KA3, and the intermediate relay KA4 to form four branches; among which, the branches where the intermediate relays KA1 and KA2 are located are respectively connected in series with the normally closed contacts of KA2 and KA1 to complete the electrical interlocking; the branches where the intermediate relays KA3 and KA4 are located are respectively connected in series with the normally closed contacts of KA4 and KA3 to complete the electrical interlocking; The normally open contacts KA1~KA4 controlled by the intermediate relays KA1, KA2, KA3 and KA4 respectively control the solenoid valve coils C1~C4 in series, forming four branches; among them, the intermediate relay KA1 is the intermediate relay controlling the unlocking solenoid valve coil C1, the intermediate relay KA2 is the intermediate relay controlling the locking solenoid valve coil C2, the intermediate relay KA3 is the intermediate relay controlling the extending solenoid valve coil C3, and the intermediate relay KA4 is the intermediate relay controlling the retracting solenoid valve coil C4.

2. The circuit device for preventing the air pump of the current collecting vehicle from burning out according to claim 1, characterized in that: The collector trolley unlocking switch S1, the collector trolley locking switch S2, the collector trolley extending switch S3, the collector trolley retracting switch S4, and the bypass switch S5 are manual switches.

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