JPS63191940A - Pressure sensor - Google Patents

Abstract

PURPOSE:To improve the safety of an opening/closing mechanism with a simple constitution by providing a pressure generation space for air tube inspection which interrupts outside air by the stroke of a valve body and increases the pressure in the inside space of an air tube through a communication hole. CONSTITUTION:The pressure generation space 23 for air tube inspection which is interrupted by the valve body 18 from the outside air and communicates with the inside space of the air tube 6 through the communication hole 10 is provided in the vicinity of the communication hole 22 where the valve body 18 has a stroke. When the valve body 18 has the stroke in the space 23, the hole 22 interrupts the outside air and the pressure in the inside space of the tube 6 increases and is detected by a pressure sensing element 13. If the air tube damages, the pressure in the inside space of the tube 6 does not varies and the pressure detection is therefore not performed. While the valve body 18 does not closes the hole 22, the space 23 communicates with the outside air. Consequently, the safety of the opening/closing mechanism is improved with the simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a pressure sensor used in an opening/closing mechanism, etc.
In particular, the present invention relates to a pressure sensor that includes an air tube, a pressure sensing element that detects pressure changes within the air tube, and an electromagnetic valve that opens and closes a communication hole to the outside air in a space formed by the air duplex using a valve body.

(Prior art and its problems) It is known that pressure sensors such as those described at the beginning are used in, for example, power windows and sunroofs of automobiles.

In other words, an air duplex connected to a pressure-sensitive element is attached to the frame of a window or sunroof, and even if a person accidentally gets caught when the window or sunroof is closed by a motor drive, the air tube will be removed when the human body comes into contact with the air tube. The increase in internal pressure is detected by a pressure sensing element, and the motor is stopped based on the output signal.

However, in the conventional example with such a configuration, if the air tube is damaged without the user's knowledge and a hole is left, air will not escape from the hole even if the human body comes into contact with it as described above. However, the pressure sensitive element did not detect the rise in pressure, which was dangerous.

(Objective of the Invention) The present invention has been made in view of the above circumstances, and an object of the present invention is to make it possible to check for damage to an air tube with a simple configuration.

(Structure and Effects of the Invention) In order to achieve such an object, the present invention provides the pressure sensor described at the beginning, in which a portion near the communication hole where the valve body strokes is isolated from outside air by the valve body. and an air tube inspection pressure generating space that communicates with the air tube inner space through the communication hole and increases the pressure in the air tube inner space as the valve body approaches the communication hole. The configuration is such that

According to this configuration, when the valve body strokes the air tube inspection generation space at the start of pressure detection, if the air tube is not damaged, the pressure in the air tube inner space increases and the pressure is detected by the pressure sensing element, and the air If the tube is damaged and there is no change in the pressure inside the air tube, the pressure sensor will not detect pressure.

Therefore, since the air tube is automatically checked when pressure detection starts, there is no need to perform a separate check operation, and since a pressure generating space for air duplication inspection is simply provided in the stroke part of the valve body, It has become easier to manufacture and can improve performance without increasing costs, making it possible to further improve the safety of the opening/closing mechanism.

(Description of Examples) Hereinafter, the present invention will be described in detail based on examples shown in the drawings. FIG. 1 is a sectional view showing a pressure sensor according to an embodiment of the present invention.

In the figure, reference numeral 1 denotes a casing, and mounting holes 2.2 are provided on both sides of the casing, and mounting portions 3.3 protrude therefrom. Reference numeral 4 denotes a cover of the casing 1, in which a communication portion 5 to the outside air and an i-connection portion 7 of the air tube 6 are integrally provided so as to protrude outward. The air tube 6 is
It is attached to the opening frame portion where the opening/closing body is provided, and is provided so as to come into contact with it when the opening/closing body is closed, and one end thereof is fitted and attached to the connection portion 7. Further, on the opposite side of the connection part 7 of the cover 4, there is integrally provided a block part 9 in which a ventilation hole 8 from the connection part 7 is continuously formed, and from the middle part of the block part 9, the ventilation hole 8 is formed continuously. 8 is configured to have a large diameter, and a communication hole 10 is provided in the large diameter portion. Reference numeral 11 denotes a printed circuit board, which is fixed by screws 12 to the end of the portion protruding from the block portion 9 in a bent shape.
The semiconductor pressure sensitive element 13 is attached by connecting the terminal to the pressure sensitive element 13, and the cylindrical part 14 extending from the pressure sensitive element 13 is fitted into the end of the vent hole 8. An amplifier 24, a differentiation circuit 25, a comparison circuit 26, etc., which will be described later, are provided on the printed circuit board 11.

In this way, by fitting the cylindrical portion 14 into the vent hole 8 and providing the pressure-sensitive element 13, the pressure-sensitive element 13 can detect changes in the pressure within the air tube 6.

Reference numeral 15 denotes an electromagnetic valve consisting of a solenoid 16, a plunger 17 that operates in response to the excitation and demagnetization of the solenoid 16, and a valve body 18 that is activated by being pressed by the end of the plunger 17. A sealing piece 19 for the communication hole 10 made of an elastic material is attached to the front surface of the valve body 18.

A portion of the valve body 18 that faces the communication hole 10 and serves as a stroke portion is partitioned from the other casing l interior space by a bent portion protruding from the block portion 9 and a partition wall 20, and the valve body 18 is located inside. A coil spring 21 is provided to bias the partition wall 20 away from the communication hole IO, and a communication hole 22 is provided near the end of the partition wall 20.

With this configuration, when the valve body 18 starts operating and its side surface closes the communication hole 22,
In the vicinity of the communication hole 10, a valve body 18 is isolated from the outside air and communicated with the inner space of the air tube 6 through the communication hole IO, and its volume increases as the valve body 18 approaches the communication hole 10. A pressure generating space 23 for air duplication inspection is formed by reducing the pressure in the air tube 6 inner space. As shown in FIG. 1, when the valve body 18 does not close the communication hole 22, the pressure generation space 23 for tube inspection is exposed to the outside air from the communication hole 22 to the inner space of the casing l, and further through the communication part 5. It is in a state where there is no communication.

FIG. 2 is a block diagram showing a circuit configuration when the pressure sensor described above is attached to, for example, a power window of an automobile.

The output of the pressure sensitive element 13 is passed through an amplifier 24 to a differentiating circuit 25.
The differentiating circuit 25 extracts the change in the amplified output and supplies the output to the comparing circuit 26. The comparator circuit 26 discriminates the differential output at a predetermined level, and provides a detection signal to the control circuit 27 if an output equal to or higher than the predetermined level is obtained.

The control circuit 27 is a power window oven switch 2.
8. Power window opening/closing input from the close switch 29, contact detection signal and air tube damage signal from the comparison circuit 26, and an open signal provided in the power window drive unit when the window opens and closes. Opening completion and closing completion signals are respectively given from the limit switch 30 and the close limit switch 31. The control circuit 27 is supplied with power from a battery 32 via an ignition switch 33.

The control circuit 27 energizes the relay coil 34 for opening the power window by the output of the close switch 29 and gives an actuation signal to the solenoid valve 15, demagnetizes the relay coil 34 by the output of the close limit switch 31, and energizes the solenoid valve 15. 15 is stopped, the open relay coil 35 is energized based on the output of the oven switch 28, and is demagnetized by the output of the close limit switch 31.

One end of the normally closed contacts 36,37 of the relay coils 34,35 are each connected to a power supply terminal, and the other end of each and one end of the normally closed contacts 38,39 are respectively connected to both ends of the motor 40. 41 is a timer and close switch 2
The control circuit 27 is activated by the output of the timer 4.
1, the relay coil 42 is energized for a predetermined time, and the energization closes the normally closed contact 44 provided between the control circuit 27 and the alarm 43.

Next, regarding the operation of this embodiment, the control circuit 2 shown in FIG.
This will be explained based on the flowchart showing the operation of step 7 and the time chart of FIG.

When the close switch 29 is turned on to close the power window (step l), actuation signals are output to the timer 41, solenoid valve 15, and relay coil 34, respectively. As a result, when the timer 41 is activated (step 2), the relay coil 42 is excited for, for example, 0.5 seconds, during which time the control circuit 27 and the alarm 43 are maintained in a conductive state, and the valve body 18 of the solenoid valve 15 is The window is operated in the closing direction (step 3), and the relay coil 34 is energized, thereby operating the motor 40 and raising the window (step 4).

In the operation of the valve body 18 described above, if the air tube 6 is not damaged and the pressure inside the air tube 6 increases when the valve body 18 strokes in the pressure generation space 23 for tube inspection, a detection signal is generated from the pressure sensor. (Step 5
),'' After the time-up of the two-legged timer 41 (step 6), the timer 41 is reset (step 7). If the air tube 6 is damaged and the pressure inside the air tube 6 does not rise and there is no detection signal from the pressure sensor (air tube damage signal), an activation signal is output to the alarm 43 and the alarm 43 sounds. Let it happen (Step 8).

After step 7, when the window is closed without being touched by a human body, the close limit switch 31h<0NL
(Step 9) Then, the output of the operating signal to the solenoid valve 15 and the relay coil 34 is stopped, and the solenoid valve 15 stops operating (Step 10).The air tube 6 of the pressure sensor is opened to the outside air, and the motor 40 is also stopped (step 11).

After step 7, if a human body or the like touches the window during the window closing operation and receives a contact detection signal from the pressure sensor (step 1
2) Stop the activation signal to the relay coil 34, output the activation signal to the relay coil 35, and reverse the motor 40.

This causes the window to open (step 13), and when the window completes its opening operation, the close limit switch 3
17><When turned ON (step 14), in response, the activation signal to the relay coil 35 is stopped, the activation signal is output to the relay coil 34, and the window is thereby closed again (step 15), and the process proceeds to step 9. return.

In step 12, upon receiving the contact detection signal,
Since the timer 41 has already timed up in step 6, there is no continuity between the control circuit 27 and the alarm 43, and therefore no alarm is issued.

In the above embodiment, the pressure sensor is used in a power window of a vehicle, but it can also be used in a sunroof of a vehicle or an opening/closing mechanism other than a vehicle.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of the pressure sensor of the present invention, FIG. 2 is a circuit block diagram showing the state of use of the present invention, and FIG.
The figure is a flowchart showing the operation of what is shown in FIG.
FIG. 4 is also a time chart. 6 is an air tube, 13 is a pressure sensitive element, 15 is a solenoid valve, 18 is a valve body, and 23 is a pressure generation space for air duplex inspection.

Claims (1)

[Claims] (1) A pressure sensor that includes an air tube, a pressure-sensitive element that detects pressure changes within the air tube, and an electromagnetic valve that opens and closes a communication hole to outside air in a space formed by the air tube using a valve body, A portion near the communication hole where the valve body strokes is blocked from outside air by the valve body and communicates with the inner space of the air tube via the communication hole, so that the valve body approaches the communication hole. A pressure sensor characterized in that a pressure generating space for testing the air tube is provided to increase the pressure in the air tube inner space as the air tube is operated.