On-delay timer
The on-delay timer addresses the challenges of harsh environments by using a robust design with relays and a CR parallel circuit in a sealed container, ensuring reliable operation and extended capacitor life for precise delay control in steel mills.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- KOBE STEEL LTD
- Filing Date
- 2023-01-11
- Publication Date
- 2026-05-29
Smart Images
Figure 0007867451000001 
Figure 0007867451000002 
Figure 0007867451000003
Abstract
Description
Technical Field
[0001] The present invention relates to an on-delay timer that can be used even in harsh environments such as steelworks.
Background Art
[0002] Conventionally, many timers have been used in devices used in steelworks, particularly in control devices for controlling cranes. Various types of timers for control have been developed. For example, there is a timer disclosed in Patent Document 1.
[0003] Patent Document 1 discloses a CR timer circuit having a configuration including an integrating circuit composed of a resistor and a capacitor connected in series between a first electric potential point and a second electric potential point, a discharge transistor connected in parallel to the capacitor that discharges the charge accumulated in the capacitor when conducting and accumulates charge in the capacitor when non-conducting, and current suction means connected to the base of the discharge transistor that sucks the charge accumulated in the base of the discharge transistor when the discharge transistor is made non-conducting.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] In the steelmaking process of a steelworks, there are many harsh environments such as "severe vibration" and "a lot of dust", and in fact, it is difficult to obtain a timer that can be used in such an environment. Regarding this point, details will be described.
[0006] First, based on the theory of electrical circuits, it is possible to construct a circuit that turns ON after a certain time constant (delay). Similarly, it is also possible to construct a circuit that turns OFF instantaneously. However, it has been difficult to construct an electronic circuit (such as an on-delay timer) that can withstand the harsh conditions of the steelmaking process.
[0007] While it is possible to obtain commercially available timers, each of the available timers (electronic timers, CR type timers, demagnetizing timers, etc.) has its own problems when used in the harsh environment of the steelmaking process.
[0008] (1) In the case of electronic timers: Electronic timers are often multifunctional, and many of them have unnecessary functions for use as timers on cranes, making them inconvenient to use. Also, electronic timers have many electronic components, and there is a risk of frequent disconnections or damage due to vibration. On a crane, vibrations are generated by impacts at joints of the running rails, etc., so the electronic components that make up the timer often break and fail. In addition, cranes are controlled by DC200V, and the current flowing for control is large, at about 1A, so there is a risk that the contacts of the relay components may weld together, causing malfunctions and other problems.
[0009] (2) In the case of CR type timers: While many off-delay timers are commercially available, there are hardly any on-delay timers available commercially that are required for crane control. This is because CR type timers utilize the discharge time of capacitor C, making it easier to construct off-delay timers. There is also the problem that the capacitors (electrolytic capacitors) used in CR circuits have a short lifespan.
[0010] (3) In the case of a demagnetizing timer: Because this timer utilizes the residual magnetic force present in the iron piece of the contactor's movable coil, the delay time is changed by adjusting the variable resistor. However, the delay time fluctuates depending on the temperature environment and voltage, making adjustment difficult and requiring considerable effort to set or change the delay time. In addition, demagnetizing timers experience significant mechanical wear, and mechanical wear occurs between the movable iron plate and coil of the demagnetizing timer, leading to malfunctions.
[0011] This invention has been made in view of the above-mentioned problems, and provides an on-delay timer that can be used even in harsh environments such as steel mills, and is particularly suitable for controlling cranes. The purpose is to provide [something]. [Means for solving the problem]
[0012] To achieve the above objectives, the present invention employs the following technical means.
[0013] In other words, the on-delay timer according to the present invention is configured such that, when the condition is ON, the first relay Ry1 and resistor R1 are connected in series between the power supply Vcc and ground, the second relay Ry2 and a normally open switch are connected in series between the power supply Vcc and ground, and a CR parallel circuit consisting of a capacitor C and a resistor R2 is provided in parallel with the first relay Ry1, and the first relay Ry1 and the CR parallel circuit are connected via a normally closed switch, and when the condition is ON, the first relay Ry1 is delayed to ON by a time constant determined by the capacitor C and resistor R1, the normally closed switch is turned ON, the CR parallel circuit is separated from the first relay Ry1, and the normally open switch is turned ON, causing the second relay Ry2 to turn ON.
[0014] Preferably, the resistor R2 is configured to dissipate the charge of the capacitor C after the CR parallel circuit is disconnected from the first relay Ry1.
[0015] Preferably, the second relay Ry2 may be constituted by a power relay.
[0016] Preferably, the first relay Ry1, the second relay Ry2, the resistor R1, and the CR parallel circuit composed of the capacitor C and the resistor R2 may be housed in a sealed container.
Effect of the Invention
[0017] The on-delay timer of the present invention is an on-delay timer that can be used even in a harsh environment such as a steel mill, and particularly an on-delay timer suitable for controlling a crane.
Brief Description of the Drawings
[0018] [Figure 1] It shows a circuit diagram of a conventional on-delay timer. [Figure 2] It shows a circuit diagram of a conventional off-delay timer. [Figure 3] It shows a circuit diagram of the on-delay timer according to the present invention.
Mode for Carrying Out the Invention
[0019] Hereinafter, an embodiment of the on-delay timer 1 according to the present invention will be described with reference to the drawings.
[0020] First, in order to understand the on-delay timer 1 of the present invention, two delay timers 100 and 200 will be described as a premise.
[0021] FIG. 1 shows a circuit diagram of a conventional on-delay timer 100. This on-delay timer 100 is a CR type on-delay timer.
[0022] First, as shown in FIG. 1, between the power supply side and the ground side of the on-delay timer 100, a CR series circuit in which a resistor R and a capacitor C are connected in series is provided. Between the power supply side and the resistor R, a switch for turning on the condition (turning on the power supply) is provided. A relay Ry is connected in parallel to the capacitor C that constitutes the CR series circuit.
[0023] Regarding the operation of this on-delay timer 100, first, when the condition is turned on (the power supply is turned on), while following the time limit of the CR circuit (the time constant of the first-order lag system), the voltage applied to the relay Ry gradually increases, and after a certain time, the relay Ry becomes ON. For example, to operate the relay Ry 3 seconds after the condition is turned on, according to the theory of the CR circuit, it is assumed that R×C = 4.292 is satisfied. While the condition is ON, the voltage is always applied to the capacitor C, so the capacitor C maintains a fully charged state.
[0024] After that, when the condition is turned off, the charge stored in the capacitor C is consumed by the internal resistance of the relay Ry. This also exhibits a time-delay behavior and operates as an off-delay timer following the time limit.
[0025] FIG. 2 shows a circuit diagram of a conventional off-delay timer 200. This off-delay timer 200 is widely available in the market.
[0026] First, as shown in FIG. 2, between the power supply side and the ground side of the off-delay timer 200, a circuit in which a capacitor C is connected is provided, and a relay Ry is connected in parallel to this capacitor C.
[0027] Regarding the operation of this off-delay timer 200, first, when the condition becomes ON, the relay R The voltage applied to y instantly rises to Vcc. This causes relay Ry to instantly turn ON. Then, when the condition is turned OFF, the charge stored in capacitor C is consumed by the internal resistance of relay Ry, and the voltage gradually approaches 0V. Relay Ry turns OFF when the voltage falls below the voltage at which it turns OFF, but until that point, it behaves with a certain time delay, operating as an off-delay timer.
[0028] With the conventional delay timers described above in mind, the on-delay timer 1 according to the present invention will now be explained.
[0029] Figure 3 shows a circuit diagram of the on-delay timer 1 according to the present invention.
[0030] As shown in Figure 3, a resistor R1 and a first relay Ry1 are connected in series between the power supply Vcc and ground. Additionally, a second relay Ry2 and a normally open switch 3 are connected in series between the power supply Vcc and ground. The first relay Ry1 and the second relay Ry2 are connected in parallel.
[0031] The first relay Ry1 is connected in parallel to a CR parallel circuit 2, which is a circuit in which a capacitor C and a resistor R2 are connected in parallel, and is connected to the first relay Ry1 via a normally closed switch 4.
[0032] The normally open switch 3 and the normally closed switch 4 are connected to the output side of the first relay Ry1 (Ry1 out ) operates as such. Therefore, when the condition is ON (power ON), the first relay Ry1 turns ON with a delay of a time constant determined by the capacitor C and resistor R1, the normally closed switch 4 turns ON, separating the CR parallel circuit 2 from the first relay Ry1, and at the same time the normally open switch 3 turns ON, causing the second relay Ry2 to turn ON.
[0033] The power supply Vcc is supplied with DC24V, and the inputs of the first relay Ry1 and the second relay Ry2 are driven by DC24V. However, the output of the second relay Ry2 is a switch for controlling the crane, and in most cases DC200V flows through it. Considering this, the second relay Ry2 is configured as a power relay.
[0034] The on-delay timer 1 of the present invention is used in steelmaking processes and therefore operates in harsh environments (high temperature, high humidity, high vibration, and high dust content). For this reason, the on-delay timer 1 of the present invention houses the first relay Ry1, the second relay Ry2, the resistor R1, and the CR parallel circuit 2 (capacitor C and resistor R2) inside a sealed container. This provides robust dust protection.
[0035] In addition, the electronic circuit board constituting the on-delay timer 1 of the present invention is supported by a vibration damper. A predetermined vibration damping effect can also be obtained by supporting at least the first relay Ry1 and the second relay Ry2 of the on-delay timer 1 with a vibration damper. This vibration damper (vibration damping means) ensures the vibration damping of the on-delay timer 1.
[0036] The operation of On Delay Timer 1 described above will be as follows when the condition is turned ON. The details of the operation are described below.
[0037] (1) The voltage across the first relay Ry1 gradually increases over a time constant (delay) determined by the values of resistor R1 and capacitor C.
[0038] (2) When the voltage rises to the ON voltage of the first relay Ry1, the first relay Ry1 turns ON, activating the normally closed switch 4, which is the output of the first relay Ry1, and disconnecting the CR parallel circuit 2 (a circuit composed of capacitor C and resistor R2) from the first relay Ry1. In other words, Ry1 turns ON and the CR parallel circuit 2 is disconnected after a time delay following the condition being turned ON.
[0039] (3) In addition, when the first relay Ry1 is turned ON, the output side of the first relay Ry1 (Ry1 out The normally open switch 3 is activated, turning on the second relay Ry2, and controlling the crane connected to the output side of the second relay Ry2.
[0040] (4) On the other hand, when the CR parallel circuit 2 is disconnected from the first relay Ry1, the charge on capacitor C is consumed and extinguished by resistor R2. However, since this CR parallel circuit 2 is disconnected from the first relay Ry1, the first relay Ry1 is in the OFF state. This is not the case. In the CR parallel circuit 2, which is disconnected from the first relay Ry1, the discharge of capacitor C is ensured, which can contribute to extending the lifespan of capacitor C.
[0041] (5) When the condition for the on-delay timer 1 of the present invention is turned OFF, the first relay Ry1 and the second relay Ry2 instantly turn OFF.
[0042] As described above, the on-delay timer 1 of the present invention is a circuit that reliably consumes the charge stored in the capacitor C in a way that does not affect the operation of the first relay Ry1 and the second relay Ry2, and instantly turns off the relays when the condition is OFF.
[0043] Furthermore, because the On-Delay Timer 1 is constructed using a minimum number of components, including electronic components that have been used for a long time (resistors, electrolytic capacitors), it is usable even in harsh environments such as steel mills (high dust, high vibration). It is well known from experience that solid-state electronic components are vulnerable to harsh environments such as steel mills (high dust, high vibration), so from this perspective as well, there is a great advantage to constructing the On-Delay Timer 1 using a minimum number of components, including electronic components that have been used for a long time (resistors, electrolytic capacitors).
[0044] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. In particular, matters not explicitly disclosed in the embodiments disclosed herein, such as operating conditions, various parameters, dimensions, weight, and volume of components, do not deviate from what is normally practiced by those skilled in the art, and the values adopted are those that can be easily anticipated by those skilled in the art. [Explanation of symbols]
[0045] 1. On-delay timer 2 CR parallel circuit 3. Normally Open Switch 4. Normally closed switch C Capacitor R1 Resistor R2 resistance Ry1 First Relay Ry2 Second Relay Vcc power supply 100 On-delay timer (conventional example) 200 Off-delay timer (conventional example)
Claims
1. A first relay (Ry1) and a resistor (R1) are connected in series between the power supply (Vcc) and ground. A second relay (Ry2) and a normally open switch are connected in series between the power supply (Vcc) and ground. A CR parallel circuit consisting of a capacitor (C) and a resistor (R2) is provided in parallel with the first relay (Ry1), and the first relay (Ry1) and the CR parallel circuit are connected via a normally closed switch. When the condition is ON, the first relay (Ry1) turns ON with a delay determined by the time constant of the capacitor (C) and resistor (R1). At the same time, the normally closed switch turns ON, separating the CR parallel circuit from the first relay (Ry1), and the normally open switch turns ON, turning the second relay (Ry2) ON. An on-delay timer characterized by the following features.
2. The on-delay timer according to claim 1, characterized in that after the CR parallel circuit is separated from the first relay (Ry1), the resistor (R2) is configured to consume the charge of the capacitor (C).
3. The on-delay timer according to claim 1, characterized in that the second relay (Ry2) is configured with a power relay.
4. An on-delay timer according to any one of claims 1 to 3, characterized in that a first relay (Ry1), a second relay (Ry2), a resistor (R1), and a CR parallel circuit consisting of a capacitor (C) and a resistor (R2) are housed in a sealed container.