JP2011126410A - Vehicle seat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively control the position of the component of a vehicle seat by eliminating the need of a pulse sensor or the like. <P>SOLUTION: This vehicle seat the component of which is operated utilizing the torque of a motor includes a current detection means for detecting the load current Vi of the motor, a voltage detection means for detecting the power voltage Vb of the motor, and a position calculation means which calculates the rotational speed N of the motor at predetermined time ΔT intervals utilizing the load current value Vi and the voltage value Vb and calculates the position W (reclining angle W) of the component based on the rotational speed N of the motor calculated at the predetermined time ΔT intervals. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle seat that operates a component member by using a rotational force of a motor.

A vehicle seat related to this is described in Patent Document 1.
The vehicle seat includes a front / rear slide mechanism that slides the seat body (constituent member) back and forth in the vehicle interior. The front / rear slide mechanism is a mechanism that slides the seat body back and forth using a screwing action of a ball screw and a nut, and is configured such that the ball screw can be rotated by a motor.
The motor of the front / rear slide mechanism is usually equipped with a pulse sensor, and is configured to output a pulse each time the motor rotates by a certain angle. For this reason, the rotation speed of the motor, that is, the rotation speed of the ball screw can be obtained by integrating the output pulses of the pulse sensor. Then, the slide amount of the seat body (the position of the seat body relative to the origin) can be obtained from the number of rotations of the ball screw by calculation.
For this reason, when the seat body reaches, for example, the forward limit position or the backward limit position, the motor can be automatically stopped.

JP 2009-248839 A

However, in the above-described vehicle seat, it is necessary to use a motor with a pulse sensor. Also, a dedicated cable for connecting the pulse sensor and the vehicle ECU is required. Furthermore, the ECU needs to have a pulse integration function.
For this reason, there exists a problem that the cost of position control of a sheet main body becomes high.

  The present invention has been made to solve the above-described problems, and the problem to be solved by the present invention is that it is possible to control the position of the constituent members of the vehicle seat at a low cost without the need for a pulse sensor or the like. Is to do.

The above-described problems are solved by the inventions of the claims.
According to a first aspect of the present invention, there is provided a vehicle seat for operating a component member by utilizing a rotational force of a motor, wherein current detecting means for detecting a load current of the motor and voltage detection for detecting a power supply voltage of the motor. And the load current value detected by the current detection means and the voltage value detected by the voltage detection means, the rotational speed of the motor is calculated every predetermined time, and every predetermined time And position calculating means for calculating the position of the constituent member based on the calculated rotation speed of the motor.

According to the present invention, since the rotation speed of the motor is calculated by using the load current value of the motor, for example, even when the load on the motor increases due to the weight of the seated person or the load on the motor decreases accurately. The rotational speed of the motor can be calculated. And since the position of a structural member is calculated based on the said motor rotational speed, the position of the said structural member can be calculated | required accurately.
For this reason, it becomes possible to omit equipment for detecting the position of the constituent member, for example, a pulse sensor attached to the motor, a pulse integrating means, and the like, and the cost can be reduced by the omission.

According to the invention of claim 2, the position calculating means calculates the rotational speed of the motor based on the average value of the load current within a predetermined time and the average value of the power supply voltage within the predetermined time. .
For this reason, the calculation accuracy of the rotational speed of the motor is improved.

According to the invention of claim 3, when the position of the component member calculated by the position calculation means becomes a predetermined position in a state where the motor operation switch is turned on, the motor is energized. It is configured to be able to stop.
For this reason, unnecessary electric power is not supplied to the motor, waste can be eliminated, and no excessive force is applied to the motor.

  According to invention of Claim 4, it is comprised so that adjustment of the inclination angle of the seat back as a structural member which can change the inclination angle with respect to a seat cushion using the rotational force of the said motor is possible. And a reclining device.

  According to the present invention, the position control of the constituent members constituting the vehicle seat can be performed at low cost.

It is a model perspective view of the vehicle seat which concerns on Embodiment 1 of this invention. It is a model side view showing the reclining function of the said vehicle seat. 1 is a block diagram schematically illustrating a seat back reclining device. It is a schematic diagram showing the drive circuit of a motor. It is a graph showing the procedure which calculates | requires the reclining angle of a seat back. It is a flowchart showing operation | movement of a reclining apparatus.

[Embodiment 1]
Hereinafter, based on FIGS. 1-6, the reclining apparatus of the vehicle seat which concerns on Embodiment 1 of this invention is demonstrated.
Here, front and rear, right and left and up and down in the figure correspond to front and rear, right and left, and up and down of the vehicle seat.

<Outline of configuration of vehicle seat 1>
The vehicle seat 1 is a seat installed in a passenger compartment of a passenger car, and includes a seat body 10 and a reclining device 20 (see FIG. 3) of the seat body 10 as shown in FIG.
The seat body 10 includes a seat cushion 12 and a seat back 14, and the seat back 14 is configured to be inclined with respect to the seat cushion 12 within a predetermined range by the action of the reclining device 20. Yes.

<About the reclining device 20>
The reclining device 20 is a device for adjusting the inclination angle of the seat back 14 of the seat body 10, and as shown in FIG. 3, the reclining mechanism 24 for inclining the seat back 14 and the reclining mechanism 24 are operated. And a control device (ECU) 22 for controlling the motor 26.
The motor 26 is a direct current brush motor and is configured to be driven by a battery 25 of a passenger car as shown in FIG.
As shown in FIG. 4, the ECU 22 includes a calculation unit 22e and a switch unit 22s. The switch portion 22s is a relay and a semiconductor switch for switching between normal rotation, reverse rotation, and stop of the motor 26. When the up switch 23u (see FIG. 3) is turned on, the forward rotation side and the down switch 23d are turned on. When it is done, it is configured to switch to the reverse side. Further, the switch unit 22s is configured so that the power supply to the motor 26 can be stopped by switching to the stop side when both the ascending switch 23u and the descending switch 23d are turned off or by a stop signal (described later) from the computing unit 22e. Has been.

The calculation unit 22e of the ECU 22 calculates the rotation speed N of the motor 26 at predetermined time intervals from the load current value Im (Vi) of the motor 26 and the power supply voltage Vb of the motor 26, and the rotation speed N at each predetermined time interval. As will be described later, the reclining angle W of the seat back 14 can be calculated based on the above. Then, as shown by the two-dot chain line in FIG. 2, when the seat back 14 is turned up to the upper limit position Su and the reclining angle W obtained by calculation becomes equal to the upper limit angle Wu, the calculation unit 22e A stop signal is output to the switch unit 22s. Also, when the seat back 14 rotates downward to the lower limit position Sd and the reclining angle W becomes equal to the lower limit angle Wd, the calculation unit 22e outputs a stop signal to the switch unit 22s.
Further, as shown in FIG. 3, the calculation unit 22e receives a signal from the origin limit switch 14m and sets the reclining angle W when the seatback 14 is at the reference position S0 (see FIG. 2) to the reference angle Ws. It is configured to be able to. Here, the origin limit switch 14m is turned on when the seat back 14 is between the reference position S0 (see the solid line) and the upper limit position Su, and is turned off when the seat back 14 is in another position. It is configured.

<Calculation method of reclining angle W>
Next, a method of calculating the reclining angle W will be described taking as an example the case where the lift switch 23u is turned on when the seat back 14 is at the reference position S0 (see FIG. 2).
When the up switch 23u is turned on and the motor 26 rotates forward, as shown in FIG. 5, for example, the load current value Im (Vi) of the motor 26 and the power supply voltage of the motor 26 (the voltage value of the battery 25) every 2 ms. ) Vb is input to the calculation unit 22e. Here, as shown in FIG. 4, the load current Im of the motor 26 is converted into a voltage Vi by a shunt resistor Rs provided in the ECU 22 and then input to the calculation unit 22 e.
The calculation unit 22e calculates the rotational speed N of the motor 26 based on the characteristics of the DC brush motor every time ΔT (ΔT = 20 ms). That is, in the electric circuit of FIG. 4, the power supply voltage Vb is expressed by Vb = (Rm + Ra) · Im + E ·· (1 expression). In this one set, Ra is an internal resistance (armature resistance) of the motor 26. Rm is a circuit resistance excluding the internal resistance Ra of the motor 26, and is a value including the shunt resistance Rs. E is an induced electromotive force of the armature A and is expressed as a function of the rotational speed N of the armature A (the rotational speed N of the motor 26). That is, the induced electromotive force E is represented by E = C × N. C is a proportionality constant.
Therefore, the rotational speed N of the motor 26 is expressed as follows by modifying the above-mentioned equation (1). N = coefficient K1 × Vb−coefficient K2 × Im
= Coefficient K1 × Vb−Coefficient K2 × Vi (2 formulas)
The computing unit 22e computes the rotational speed N of the motor 26 every time ΔT (ΔT = 20 ms) based on these two equations.

For example, as shown in FIG. 5, when the power supply voltage value Vb1 and the load current value Vi1 after ΔT time (20 ms) after the motor 26 is started, the calculation unit 22e sets the voltage value Vb1 and the load current value Vi1. Based on this, the rotational speed N1 of the motor 26 (N1 = coefficient K1 × Vb1−coefficient K2 × Vi1) is calculated.
Next, the calculation unit 22e calculates the rotation angle N1ΔT when the motor 26 rotates at the rotation speed N1 for ΔT time, and calculates the reclining angle change amount W1 based on the rotation angle N1ΔT. Here, since the reclining angle change amount W1 is a function of the rotation angle N1ΔT of the motor 26, the reclining angle change amount W1 is expressed by W1 = coefficient K3 × N1ΔT. The coefficient K3 is a constant determined by the gear ratio of the reclining mechanism 24 and the like.
Then, the calculation unit 22e adds the reclining angle change amount W1 to the reference angle Ws. That is, the reclining angle W after ΔT time (20 ms) from the start of the motor 26 is represented by the reference angle Ws + W1 (see the upper part of FIG. 5).

Similarly, when the voltage value after 2 × ΔT time after the start of the motor 26 is Vb2 and the load current value is Vi2, the calculation unit 22e rotates the rotation speed of the motor 26 based on the voltage value Vb2 and the load current value Vi2. N2 (N2 = coefficient K1 * Vb2-coefficient K2 * Vi2) is calculated. Then, the calculation unit 22e calculates the rotation angle N2ΔT when the motor 26 rotates at the rotation speed N2 for ΔT time and the reclining angle change amount W2 at that time, and the reclining angle change amount W2 is calculated as the reference angle. Add to Ws + W1.
That is, the reclining angle W after 2 × ΔT time (20 ms) from the start of the motor 26 is represented by the reference angle Ws + W1 + W2.

Similarly, when the voltage value after 3 × ΔT time after the start of the motor 26 is Vb3 and the load current value is Vi3, the calculation unit 22e rotates the rotation speed of the motor 26 based on the voltage value Vb3 and the load current value Vi3. N3 (N3 = coefficient K1 × Vb3—coefficient K2 × Vi3) is calculated. Then, the calculation unit 22e calculates the rotation angle N3ΔT when the motor 26 rotates at the rotation speed N3 for ΔT time and the reclining angle change amount W3 at that time, and uses the reclining angle change amount W3 as the reference angle. Add to Ws + W1 + W2.
That is, the reclining angle W after 3 × ΔT time (20 ms) from the start of the motor 26 is represented by the reference angle Ws + W1 + W2 + W3.
In this way, while the motor 26 is being driven, the rotational speed N, rotational angle NΔT, and reclining angle variation W1, W2,... Of the motor 26 are calculated every predetermined time ΔT to obtain the reclining angle W. Be able to.

<Operation of the reclining device 20>
Next, the operation of the reclining device 20 will be described based on the flowchart of FIG. Here, the process shown in the flowchart of FIG. 6 is repeatedly executed, for example, every 2 ms in the calculation unit 22e of the ECU 22.
First, when the raising switch 23u is turned on with the seat back 14 in the reference position S0 (reclining angle W = Ws) (YES in step S100, NO in step S101), the motor 26 is activated in the forward rotation direction. (Step S102). Then, the voltage value Vb and load current value Vi of the motor 26 at that time are input to the calculation unit 22e (step S103). Next, it is determined whether or not the calculation timing (ΔT time (20 ms) has elapsed) (NO in step S104), and the process returns to step S100. Then, the processing from step S100 to step S104 is repeatedly executed until the calculation timing is reached, that is, until ΔT time (20 ms) elapses after the motor 26 is started.

Thus, when the calculation timing comes (YES in step S104), as shown in FIG. 5, the rotational speed N1 of the motor 26 is calculated based on the voltage value Vb1 and the load current value Vi1 at that time (step S105). (See FIG. 5). Next, the rotation angle N1ΔT when the motor 26 rotates at the rotation speed N1 for ΔT time and the reclining angle change amount W1 at that time are calculated, and the reclining angle change amount W1 is added to the reference angle Ws. Is done. That is, the reclining angle W (reference angle Ws + W1) after ΔT time (20 ms) from the start of the motor 26 is calculated (step S106, step S107).
If the calculated reclining angle W is not the upper limit angle Wu (NO in step S108), the process returns to step S100. Then, while the motor 26 is driven to rotate forward, the processing from step S100 to step S108 is repeatedly executed. Thus, when the calculated reclining angle W becomes equal to the upper limit angle Wu (YES in step S108), the switch portion 22s of the ECU 22 is switched to the stop side and the energization of the motor 26 is stopped (step S109). As a result, the seat back 14 is held at the upper limit position Su.

Here, even if the reclining angle W is equal to the upper limit angle Wu, if the ascending switch 23u is further turned on, the determination in step S100 is YES, so that the reclining angle W is again set to the upper limit angle in step S101. It is determined whether or not Wu. At this time, since the determination in step S101 is YES, the process proceeds to step S109, and the energization stop of the motor 26 is continued in step S109.
Further, when the raising switch 23u is turned off before the reclining angle W reaches the upper limit angle Wu (NO in step S100), the energization of the motor 26 is stopped at that time (step S109). Thereby, the seat back 14 is held at this position.

Further, when the lower switch 23d is turned on while the seat back 14 is at the reference position S0 (the reclining angle W = Ws), the reclining control is performed in the same procedure as when the up switch 23u is operated. When the seat back 14 is rotated (lowered) downward from the reference position S0, the reclining angle W is obtained by subtracting the reclining angle change amounts W1, W2,... From the reference angle Ws.
Even when the seat back 14 is at a position other than the reference position S0, when the raising switch 23u is turned on, the reclining angle change amounts W1, W2,... Are added to the reclining angle Wx at that position. A reclining angle W is determined. When the lowering switch 23d is turned on, the reclining angle W is obtained by subtracting the reclining angle change amounts W1, W2,... From the reclining angle Wx at that position.

That is, the seat back 14 corresponds to a structural member of the vehicle seat of the present invention, and the calculation unit 22e of the ECU 22 corresponds to a current detection unit, a voltage detection unit, and a position calculation unit of the present invention. Further, the shunt resistance Rs of the ECU 22 corresponds to the current detection means of the present invention.
The up switch 23u and the down switch 23d correspond to the operation switch of the present invention.
Further, the upper limit angle Wu and the lower limit angle Wd of the seat back 14 correspond to predetermined positions of the constituent members of the present invention.

<Advantages of vehicle seat 1>
According to the vehicle seat 1 according to the present embodiment, since the rotational speed N of the motor 26 is calculated using the load current value Im (Vi) of the motor 26, for example, the load on the motor 26 is based on the weight of the seated person. Even when the load increases or the load on the motor 26 decreases, the rotational speed N of the motor 26 can be accurately calculated. In order to calculate the reclining angle W based on the rotational speed N, the reclining angle W can be obtained with high accuracy.
For this reason, a device for detecting the reclining angle W, for example, a pulse sensor attached to the motor 26, a pulse integrating means, and the like can be omitted, and the cost can be reduced by the omission.
Further, even when the ascending switch 23u or the descending switch 23d is turned on, the power supply to the motor 26 can be stopped when the reclining angle W becomes the upper limit angle Wu or the lower limit angle Wd. ing. For this reason, unnecessary electric power is not supplied to the motor 26, waste can be eliminated, and excessive force is not applied to the motor 26.

<Example of change>
Here, the present invention is not limited to the above-described embodiment, and modifications can be made without departing from the gist of the present invention. For example, in this embodiment, the example which calculates the rotational speed N of the motor 26 based on the voltage value Vb of the motor 26 and load current value Vi for every time (DELTA) T was shown. However, the average of the voltage value Vb of the motor 26 and the average of the load current value Vi are obtained during the time ΔT, and the rotational speed N of the motor 26 is calculated based on the voltage average value Vbav and the load current average value Viav. Is also possible. Thereby, the calculation accuracy of the rotational speed N of the motor 26 is improved.
In this embodiment, the rotational speed N of the motor 26 is obtained from the voltage value Vb and the load current value Vi, the rotational angle NΔT of the motor 26 for ΔT time is obtained from the rotational speed N, and further the rotational angle NΔ. The example which calculates | requires the reclining angle W based on T was shown. However, the relationship between the rotational speed N of the motor 26, the rotational angle NΔT, and the reclining angle W is calculated in advance, and is directly calculated from the voltage value Vb and load current value Vi for each ΔT time of the motor 26. It is also possible to obtain the reclining angle W.
In the present embodiment, an example in which the present invention is applied to the reclining device 20 of the vehicle seat 1 has been described. However, the present invention can also be applied to a seat slide device or a seat rotation device instead of the reclining device 20. is there.

14 ... Seat back (component)
20: Recliner 22 ... ECU
22e ··· Calculation unit (current detection means, voltage detection means, position calculation means)
Rs: Shunt resistance (current detection means)
23u ... Ascent switch (switch for operation)
23d ··· Descent switch (operation switch)
26... Motor Im (Vi), load current value N, rotation speed Vb, voltage value (power supply voltage value)
W ... Reclining angle Ws ... Reference angle Wu ... Upper limit angle (predetermined position)
Wd: Lower limit angle (predetermined position)

Claims (4)

A vehicle seat for operating a constituent member by using a rotational force of a motor,
Current detection means for detecting a load current of the motor;
Voltage detection means for detecting a power supply voltage of the motor;
Using the load current value detected by the current detection means and the voltage value detected by the voltage detection means, the rotational speed of the motor is calculated every predetermined time, and is calculated every predetermined time. Position calculating means for calculating the position of the component based on the rotational speed of the motor;
A vehicle seat comprising: The vehicle seat according to claim 1,
The position calculating means calculates a rotational speed of the motor based on an average value of the load current within the predetermined time and an average value of the power supply voltage within the predetermined time. . A vehicle seat according to claim 1 or 2, wherein
A configuration in which energization of the motor can be stopped when the position of the component calculated by the position calculation means reaches a predetermined position in a state where the switch for operating the motor is turned on. A vehicle seat characterized by being made. A vehicle seat according to any one of claims 1 to 3, wherein
A seat back as the component configured to change an inclination angle with respect to the seat cushion; and
A reclining device configured to be able to adjust the inclination angle of the seat back using the rotational force of the motor;
A vehicle seat comprising:

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