Control device for sealing valves

Abstract

In a control device for a sealing valve, the device ensures that the sealing valve can be reliably closed when a closing request is made, while also suppressing the noise of the sealing valve striking the vehicle interior that occurs during initialization. [Solution] In response to a request to close the sealing valve 1, which is opened and closed by the stepping motor 2, the control device 3 performs a valve closing process that rotates the stepping motor 2 in the valve closing direction by a predetermined number of steps, and also performs initialization from the point when the stepping motor 2 stops during the valve closing process. The initialization alternately repeats a drive process that rotates the stepping motor 2 an additional predetermined number of steps in the valve closing direction from the point when the stepping motor 2 stops during the drive process, and a stop process that maintains the stopped state of the stepping motor 2 for a predetermined time from the point when the stepping motor 2 stops during the drive process.

Description

Technical Field

[0001] The present invention relates to a control device for a shutoff valve.

Background Art

[0002] For example, Patent Document 1 describes that "in a vehicle in which the internal combustion engine is stopped and restarted based on vehicle driving conditions during vehicle driving, initialization of a flow control valve that is opened and closed by a stepping motor is performed at the time of restart." The initialization continuously drives the stepping motor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above Patent Document 1, for example, a knocking sound against a stopper (valve seat) of a flow control valve repeatedly occurs for a long time with the execution of the initialization. Therefore, when the surroundings are quiet, such as when the engine is stopped and the vehicle is in a stopped state, there is a concern that the knocking sound may resonate in the vehicle interior and increase the possibility of giving discomfort to the passengers.

[0005] In view of such circumstances, an object of the present invention is to make it possible to surely close a shutoff valve when a valve closing request for the shutoff valve is made, and to suppress the knocking sound of the shutoff valve associated with the execution of initialization from resonating in the vehicle interior.

Means for Solving the Problems

[0006] The present invention relates to a control device that, in response to a request to close a sealing valve opened and closed by a stepping motor, performs a valve closing process by rotating the stepping motor in the valve closing direction by a predetermined number of steps, and also performs initialization from the point at which the stepping motor stops during the valve closing process, wherein the initialization is characterized by alternately repeating a drive process that rotates the stepping motor an additional predetermined number of steps in the valve closing direction from the point at which the stepping motor stops during the drive process, and a stop process that maintains the stopped state of the stepping motor for a predetermined time from the point at which the stepping motor stops during the drive process.

[0007] In this configuration, the stepping motor is driven intermittently during the initialization process. This not only ensures that the sealing valve is reliably closed when a closing request is made for the sealing valve, but also shortens the time required for each of the multiple intermittently executed drive processes during initialization compared to conventional examples.

[0008] As a result, even if a rattling sound is generated when the sealing valve's stopper (valve seat) is executed in a single drive step during initialization, the duration of the rattling sound will be shorter than in conventional cases, and the timing of the rattling sound will be extended, thereby suppressing the rattling sound from resonating inside the vehicle.

[0009] Therefore, in order to ensure that the sealing valve can be reliably closed when a closing request is made for the sealing valve, it becomes possible to make it difficult for the occupants to perceive the abrupt noise that may occur when the initialization is performed, even when the surroundings are quiet, such as when the engine and vehicle are stopped.

[0010] By the way, in the above-mentioned control device, it is preferable that the valve closing process in response to the valve closing request rotates the stepping motor at a low speed so as not to cause it to lose step.

[0011] Furthermore, in the control device described above, it is possible to set the stopping time for each of the stopping processes to be longer than the time required for each of the driving processes. [Effects of the Invention]

[0012] The control device for a sealing valve according to the present invention makes it possible to reliably close the sealing valve when a closing request is made, and also to suppress the generation of a noise when the sealing valve abuts during initialization. This makes it less likely for the occupants to perceive the noise when the sealing valve abuts during initialization, thus reducing the possibility of causing discomfort to the occupants. [Brief explanation of the drawing]

[0013] [Figure 1] This is a circuit diagram including a control device for a sealing valve according to the present invention. [Figure 2] This figure shows a timing chart illustrating initialization according to one embodiment of the control device for a sealing valve according to the present invention. [Figure 3] This figure shows another timing chart illustrating the initialization according to another embodiment of the control device for a sealing valve according to the present invention. [Modes for carrying out the invention]

[0014] The best embodiment for carrying out the present invention will be described in detail below with reference to the accompanying drawings.

[0015] Figures 1 and 2 show one embodiment of the present invention. In the figures, 1 is a sealing valve, 2 is a stepping motor, and 3 is a control device.

[0016] The sealing valve 1 is installed, for example, between the fuel tank and the canister (not shown). The stepping motor 2 opens or closes the sealing valve 1 by rotating its pivot shaft (not shown) in the forward or reverse direction. The rotation angle of the stepping motor 2 is known, but is controlled by the number of drive pulses input from a drive circuit (not shown).

[0017] The control device 3 controls the rotation direction and the number of steps of the stepping motor 2 in response to an open valve request or a close valve request of the blocking valve 1, and is composed of, for example, an ECU (Electronic Control Unit).

[0018] Although not shown in detail, this ECU includes a CPU, a ROM, a RAM (also referred to as a memory), a communication I / F, and an input / output I / F that are communicably connected to each other via a bus.

[0019] After reaching the closed valve position in response to the close valve request of the blocking valve 1, this control device 3 executes initialization. The initialization in this embodiment drives the stepping motor 2 intermittently.

[0020] Next, referring to FIG. 2, the opening / closing operation of the blocking valve 1 by the control device 3 in this embodiment will be described in detail. In FIG. 2, the vertical axis represents the number of steps of the stepping motor 2, and the horizontal axis represents time.

[0021] First, when the blocking valve 1 is in the closed state and an open valve request for the blocking valve 1 is made at time t1, the blocking valve 1 is rotated to the open valve position at time t2 by rotating the stepping motor 2 by a predetermined number of steps (So) in the open valve direction. The time (Tx) required for this open valve is arbitrary, but is performed in a relatively short time.

[0022] When the blocking valve 1 is in the open state as described above and a close valve request for the blocking valve 1 is made at time t3, the blocking valve 1 is rotated to the closed valve position at time t4 by driving the stepping motor 2. The time (Ty) required for this close valve is arbitrary, but is performed in a relatively short time as in the time (Tx) required for the open valve.

[0023] If the close valve is performed in a short time as described above, the stepping motor 2 may fall out of synchronization, so initialization is performed to ensure closing of the valve.

[0024] Next, the initialization process will be explained in detail.

[0025] First, from the point (t4) when the sealing valve 1 reaches the closed position as described above, the stepping motor 2 is rotated an additional predetermined number of steps in the closing direction (driving process).

[0026] Next, the stopping state of the stepping motor 2 from the point at which it stops in the drive process (t5) is maintained for a predetermined time (T10) (stopping process).

[0027] After this, the drive process and the stop process are repeated alternately for a predetermined number of times (N). In this embodiment, the stop time for each stop process is set to be the same as the time required for each drive process, but it can be set arbitrarily. If the stop time for each stop process is set to be longer than the time required for each drive process, a longer cycle time can be secured for the stepping motor 2 to transition from one drive process to the next, which is advantageous in preventing the start timing of the stepping motor 2 from being off.

[0028] The total number of steps (-Se) of the stepping motor 2 from the start to the end of such initialization, that is, the total number of steps (-Se) of the multiple drive processes performed intermittently during initialization, can be set arbitrarily, but for example, it can be set to be the same as the number of steps (Sm) of the stepping motor 2 required to bring the sealing valve 1 to the opening limit.

[0029] As described above, in the embodiment to which the present invention is applied, the stepping motor 2 is driven intermittently during initialization. This not only ensures that the sealing valve 1 is reliably closed when a closing request is made, but also shortens the time required for each of the multiple drive processes that are intermittently executed during initialization compared to the conventional example.

[0030] As a result, even if a noise is generated when the sealing valve 1 hits the stopper during one drive cycle in the initialization, the duration of the noise will be shorter than in the conventional example, and the timing of the noise will be extended, thus suppressing the noise from resonating inside the vehicle.

[0031] Therefore, by ensuring that the sealing valve 1 can be reliably closed when a closing request is made for the sealing valve 1, and by making it less likely for the occupants to perceive the abrupt noise that may occur when the initialization is performed, even when the surroundings are quiet, such as when the engine and vehicle are stopped, the possibility of causing discomfort to the occupants can be reduced.

[0032] It should be noted that the present invention is not limited to the embodiments described above, and can be modified as appropriate within the scope of the claims and equivalents thereof.

[0033] For example, Figure 3 shows another embodiment of the present invention. In this embodiment, as in the embodiment shown in Figure 2, the stepping motor 2 is rotated at the lowest possible speed to prevent it from losing step when a closing request is made for the sealing valve 1. In other words, when a closing request is made for the sealing valve 1 at time t3, the drive of the stepping motor 2 is controlled so that the time required for closing (Tz) is longer than the time (Ty) in Figure 2.

[0034] In this embodiment, initialization is performed by repeating the drive process and the stop process alternately a predetermined number of times (N), similar to the embodiment shown in Figure 2. In this embodiment, the stop time for each stop process is set to be the same as the time required for each drive process, but it can be set arbitrarily.

[0035] In this embodiment, the valve closing process is performed at the lowest possible speed to prevent the stepping motor 2 from losing step. Therefore, the number of individual steps in the intermittently executed drive process during initialization can be set to be fewer than in the embodiment shown in Figure 2.

[0036] As a result, the total number of steps (-Se) of the stepping motor 2 from the start to the end of the initialization can be set to be less than in the embodiment shown in Figure 2, and therefore the total processing time required for the initialization can be shortened compared to the embodiment shown in Figure 2.

[0037] As a result, the sealing valve 1 can be reliably closed when a closing request is made for it, and even when the surroundings are quiet, such as when the engine and vehicle are stopped, it becomes possible to make it difficult for the occupants to perceive the sound of the sealing valve 1 hitting the ground, which may occur when the initialization is performed, thereby reducing the possibility of causing discomfort to the occupants. [Industrial applicability]

[0038] The present invention can be suitably used in a control device for a sealing valve. [Explanation of Symbols]

[0039] 1. Sealing valve 2 Stepping motors 3. Control device

Claims

[Claim 1] A control device that, in response to a request to close a sealing valve opened and closed by a stepping motor, performs a valve closing process by rotating the stepping motor in the closing direction for a predetermined number of steps, and also performs initialization from the point in time when the stepping motor stops during the valve closing process, The control device for a sealing valve is characterized by the following alternating steps in the initialization process: a drive step in which the stepping motor is rotated an additional predetermined number of steps in the valve closing direction from the point in time when the stepping motor is stopped, and a stop step in which the stopped state of the stepping motor is maintained for a predetermined time from the point in time when the stepping motor is stopped during the drive step.

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