JPH04102442U - Automobile tire pressure monitoring device - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an automobile tire pressure monitoring device that can reliably check the air pressure of automobile tires without requiring a complicated configuration. [Structure] The signal output device 2, 3 includes a pressure detection member 22 for electrically detecting the application of pressure and outputs a detection signal S related to the ground contact area of the tire T to be measured. The detection signal S
The determination device 4 determines whether or not the air pressure of the tire T to be measured is normal by comparing it with a signal that should be used as a predetermined reference.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is a monitoring device for monitoring whether the air pressure of automobile tires is appropriate. related.

0002

[Conventional technology]

Traditionally, pressure sensors installed on the tire side have been used to monitor the air pressure in automobile tires. A method of guiding the output from the sensor to the vehicle body through an appropriate transmission means and displaying it, and tires. The wheel rotation speed, vehicle height, vibration, etc. per specified mileage change depending on the air pressure of the vehicle. A method of estimating tire air pressure using this fact has been considered. But before This method requires a complicated configuration to transmit the output from the pressure sensor to the vehicle body. Not only that, but the structure of the tire itself is complicated, so the latter method is more practical. , is viewed as promising.

0003

[Problem that the idea aims to solve]

However, even when using the latter method, it is difficult to determine whether the tire pressure is normal or abnormal. In addition to requiring complex signal processing circuits, load sensors, vehicle speed sensors, and steering In order to obtain reliable judgment results due to the need for angle sensors, etc. must properly evaluate a large number of input signals, and the algorithm for this purpose is The problem is that it is extremely complicated. The aim of the invention is therefore to inflate automobile tires without the need for complex configurations. A car tire pressure monitoring device that can reliably check air pressure. It is about providing.

0004

[Means to solve the problem]

The feature of this invention to solve the above problem is that the application of pressure is detected electrically. outputs a detection signal related to the ground contact area of the tire to be measured. The signal output device compares the detection signal with a signal that should be used as a predetermined standard. and a determination device for determining whether the air pressure of the tire to be measured is normal or not. .

[0005]

[Effect]

When the tire to be measured is placed on the pressure detection member, the pressure is determined by the tire. The sensing member receives pressure, but at this time, the area to which pressure is applied is the area of the tire. It is determined according to the ground contact area, that is, the tire air pressure, and the signal output device A detection signal related to the ground contact area of the player is output. The detection signal is determined as appropriate. The reference signal is compared with the discrimination device, and the tire pressure is determined based on the comparison result. It is determined whether it is normal or not.

[0006]

【Example】

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 schematically shows the configuration of a tire pressure monitoring device 1 according to the present invention. Ru. The tire pressure monitoring device 1 determines whether the tire pressure of the car A is normal or not. It is configured to determine and monitor by detecting the ground contact area of the tire T to be measured. It has a sensor 2 for outputting electrical data regarding the ground area.

[0007] The sensor 2 includes a piezoelectric ceramic element on a substrate 21, as shown in detail in FIG. A large number of piezoelectric sensing segments 22 are arranged in rows and columns to detect the tire. When the tire T is placed on the sensor 2, the bottom of the tire T corresponding to the ground contact part of the tire T is Pressure is applied only to the bedded piezoelectric sensing segments. Each piezoelectric sensing segment Each of the ports 22 outputs an electric signal corresponding to the applied pressure at that time.

[0008] Returning to FIG. 1, a sensor consisting of each output voltage signal from piezoelectric sensing segment 22 The output signal R is input to a signal processing circuit 3 which together with the sensor 2 constitutes a signal output device. Here, the level of the output voltage signal is set to a predetermined level for all output voltage signals. Level discrimination is performed to determine whether the level is greater than or equal to A detection signal S corresponding to the ground contact area of the tire T, that is, the air pressure of the tire T is output. It will be done.

[0009] In other words, when the air pressure of the tire T is at a normal value, as shown in FIG. 3(A), However, the ground contact area of the tire T is small, so the piezoelectric pressure applied by the tire T The number of detection segments is small. However, when the air pressure of the tire T decreases, the As shown in (B), the contact area of the tire T becomes larger, and the piezoelectric sensor under pressure The number of segments will increase.

0010 Therefore, the level of the output voltage from the piezoelectric sensing segment is adjusted to the level described above. By discriminating, the number of piezoelectric sensing segments under the tire T can be detected. This makes it possible to output a detection signal S corresponding to the air pressure of the tire T. Ru. In the illustrated embodiment, the greater the number of piezoelectric sensing segments under pressure, the more The signal processing circuit 3 is configured so that the level of the output signal S increases.

[0011] Returning to FIG. 1, the detection signal S is input to the discrimination circuit 4, where it is determined that the tire T is normal. The level is compared with the upper limit value of the detection signal S when the air pressure is It is determined whether the tire air pressure is normal or not.

0012 The discrimination output D from the discrimination circuit 4 is input to the display device 5, where the tire to be measured T is displayed. Displays whether the air pressure is normal or abnormal.

[0013] According to this configuration, the sensor 2 provides information regarding the size of the ground contact area of the tire T. Obtain a sensor output signal R having information, and send this sensor output signal R to the signal processing circuit 3. By processing this, a detection signal S indicating the air pressure of the tire T is obtained. detection The signal S is compared with an appropriate reference signal in the discrimination circuit 4, and the comparison result is Accordingly, a determination signal D indicating whether or not the air pressure of the tire T is normal is output.

[0014] Therefore, the air pressure of the tire T can be checked with an extremely simple configuration. By placing the sensor 2 on the road, for example, it is possible to pay tolls at expressway toll gates. Easily check the tire pressure when you stop to pay your vehicle or during a stop due to a red light. It is possible to configure a tire pressure monitoring system to check.

[0015] Note that in the above embodiment, the sensor 2 is composed of a large number of piezoelectric detection segments. , this piezoelectric sensing segment may be made from piezoelectric polymers, piezoelectric composites, etc. good.

[0016] Furthermore, as shown in FIG. 4, a large number of wire-shaped piezoelectric sensing members 23 are The configuration is such that they are arranged parallel to each other at intervals, and the wire-like wires underlain by the tires are A configuration may also be adopted in which the number of piezoelectric detection members is electrically counted and the detection signal S is generated. i.e. , if the tire pressure is high, the tire may become under the tire as shown in Figure 4 (A). The number of electric wire-shaped piezoelectric detection members is small, and when the tire air pressure becomes low, (B ), the number of wire-like piezoelectric sensing members that are underneath the tire increases. A signal with a level corresponding to this number can be obtained as the detection signal S.

[0017] Furthermore, the configuration of the sensor 2 is not limited to one using a piezoelectric element, and is shown in FIG. A large number of electrodes 25 are provided on one side of a plate member 24 made of pressurized conductive rubber. By measuring the resistance value between these electrodes 25 using the sensor 26, pressurized conduction is detected. The size of the area where the plate member 24 made of rubber is in a predetermined conductive state is detected, and this A detection signal S indicating the detection result may be obtained.

[0018] FIG. 5(A) shows the case where the air pressure of the tire T is high, and FIG. 5(B) shows the case where the tire T has a high air pressure. This shows a case where the tire air pressure is low.

[0019] In this way, the sensor 2 can output electrical information in response to tire pressure. Any suitable pressure sensing element can be used, which can be used to detect the tire's contact surface. Any configuration that outputs an electrical signal related to the product may be used.

[0020] In the above example, only one sensor 2 is used to check the air pressure of one tire. However, the present invention is not limited to the configuration of the above embodiment, and may include multiple configurations. Tire pressure can be determined by comparing the air pressure of multiple tires using It is also possible to have a configuration that performs monitoring, and another example with such a configuration is shown in the figure. 6.

[0021] In FIG. 6, 61 to 64 are first to fourth signal output devices, which are used for an automobile (not shown). The contact area of each of the four tires T1 to T4 is electrically detected, and the ground contact area of each of the four tires T1 to T4 is electrically detected. The first to fourth detection signals S1 to S4 indicating the ground contact area of 4 are the first to fourth signal outputs. The signals are output from devices 61 to 64, respectively. Each of the first to fourth signal output devices 61 to 64 Each configuration is a signal consisting of a combination of a sensor 2 and a signal processing circuit 3 shown in FIG. The configuration can be similar to that of the signal output device.

[0022] The first to fourth detection signals S1 to S4 are input to the maximum value detection circuit 65, Here, the signal with the highest level is detected and the level of the detected signal is the same. A signal of the same level is output as the maximum value signal M. On the other hand, the first to fourth detection signals S1 to S4 are input to the minimum value detection circuit 66, where the lowest level The signal at the same level as the detected signal is the minimum value. It is output as signal L.

[0023] The maximum value signal M and the minimum value signal L are input to a calculation circuit 67, where M/L Calculates the data that shows the relative difference between the largest and smallest ground contact areas. The data RT is calculated, and a detection signal S indicating this data RT is output.

[0024] The detection signal S is input to the determination circuit 68, where it is determined that the tire air pressure is normal. If RT is less than RTA, the tire is empty. The air pressure is determined to be normal, but if RT is greater than RTA, the tire pressure may be incorrect. It is considered normal. A determination signal D indicating this determination result is input to the display device 69, Here, a display regarding whether the tire air pressure is normal or abnormal is displayed.

[0025]

[Effect of the idea]

According to the present invention, as described above, the sensor and circuit for detecting air pressure are installed on the automobile side. Since no installation is required, tire pressure can be checked easily on all vehicles. This can be done conveniently and can greatly contribute to ensuring safe driving of automobiles. Also, as mentioned above, for cars that are already equipped with a tire pressure detection device. By checking the tire pressure, you can check the tire pressure from both the car side and the road side. This resulted in a double check, and a malfunction occurred in the car's tire pressure detection device. If so, you can check whether the detection has ended and back it up. , the reliability of tire pressure monitoring can be further improved.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a tire pressure monitoring device according to the present invention.

FIG. 2 is an enlarged plan view showing the sensor of FIG. 1 in enlarged detail;

FIG. 3 is an explanatory diagram for explaining the operation of the device in FIG. 1;

FIG. 4 is a plan view showing another embodiment of the sensor shown in FIG. 1;

FIG. 5 is a plan view showing another embodiment of the sensor of FIG. 1;

FIG. 6 is a block diagram showing another embodiment of the present invention.

[Explanation of symbols]

2 sensor 3 Signal processing circuit 4 Discrimination circuit 22 Piezoelectric detection segment 61 First signal output device 62 Second signal output device 63 Third signal output device 64 Fourth signal output device 65 Maximum value detection circuit 66 Minimum value detection circuit 67 Calculation circuit 68 Discrimination circuit S detection signal D Discrimination signal

Claims (1)

[Scope of utility model registration request] 1. A signal output device that includes a pressure detection member for electrically detecting the application of pressure and outputs a detection signal related to the ground contact area of a tire to be measured; 1. A tire pressure monitoring device for an automobile, comprising: a determination device for determining whether or not the tire pressure to be measured is normal by comparing it with a signal to be measured.