JP2007127586A - Pressure detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure detector capable of detecting the pressure of a fastening face of a disk wheel. <P>SOLUTION: The pressure detector 10 is provided with a pressure detection portion 20 which is interposed between the disk wheel and a hub, and detects a pressure applied to the fastening face in a state of fastening the disk wheel and the hub, a controller 40 for discriminating information on the fastening face from the pressure, and a reporting portion 30 for reporting the discriminated information on the fastening face. As a result, by detecting the pressure applied to the fastening face of the disk wheel and the hub, information on the fastening face based on the detected pressure, e. g. information that tightening torque of the disk wheel to the hub is not proper, information that input from a vehicle by its load is excessive can be reported to its driver or the like. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pressure detection device that detects the pressure of a fastening surface between a disc wheel and a hub.

  Conventionally, in order to visually confirm the overall tightening pressure when mounting the mounting device on the installation surface, Patent Document 1 discloses that a pressure-sensitive sheet that changes color due to pressure is inserted between the mounting device and the mounting surface. A clamping pressure detection method for detecting a clamping pressure by discoloring a pressure sheet is disclosed.

In addition, in order to detect the tightening state of a hub nut that fixes a tire to a hub provided on an axle of an automobile or the like, Patent Document 2 electrically detects the contact state between a conductive bracket and the hub nut. A tire abnormality detection device is disclosed.
JP 2002-202213 A Japanese Utility Model Publication No. 6-63405

  However, the tightening pressure detection method disclosed in Patent Document 1 merely detects the tightening pressure when the mounting device is mounted on the installation surface. Further, the tire abnormality detection device disclosed in Patent Document 2 can only detect abnormality due to non-contact and poor contact between the bracket and the hub nut.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a pressure detection device capable of detecting the pressure of the fastening surface of the disc wheel.

  In order to solve the above-described problems, a pressure detection device according to an aspect of the present invention includes a unit that is sandwiched between a disc wheel and a hub and detects pressure applied to a fastening surface in a state where the disc wheel and the hub are fastened. Prepare.

  According to this aspect, the pressure applied to the fastening surface between the disc wheel and the hub can be detected, and the fastening state between the disc wheel and the hub can be known. Therefore, for example, when the tightening torque of the disc wheel to the hub is not appropriate, or when the load is excessive, it is possible to notify an occupant, disk wheel replacement, or an operator at the production site (hereinafter referred to as an occupant).

  Another embodiment of the present invention is also a pressure detection device. The pressure detection device is sandwiched between a disc wheel and a hub, detects a pressure applied to a fastening surface in a state where the disc wheel and the hub are fastened, and discriminates information of a fastening surface from the pressure. A control unit, and a notification unit for reporting information on the determined fastening surface.

  According to this aspect, the pressure applied to the fastening surface between the disc wheel and the hub is detected, and the fastening surface information based on the detected pressure, for example, the information that the fastening torque of the disc wheel to the hub is not appropriate or the load amount Information that the input from the vehicle is excessive can be notified to the passenger or the like.

  The control unit stores a predetermined value for comparison with a signal value corresponding to the pressure, and information notified by the notification unit by comparing the signal value with the predetermined value. And a computing unit for discrimination.

  According to this aspect, by comparing the predetermined value stored in the storage unit and the signal value having a correspondence relationship with the pressure by the calculation unit, the information notified by the notification unit, for example, the disc wheel to the hub It is possible to determine information that the tightening torque is not appropriate and information that the input from the vehicle due to the load is excessive.

  In addition, the above-described pressure detection device further includes a vehicle state detection unit that detects a vehicle state, and the control unit detects a predetermined value for comparison with a signal value having a correspondence relationship with the pressure. It is preferable that a plurality of storage units stored in response to the information and a calculation unit that determines information to be notified by the notification unit by comparing the signal value and the predetermined value according to the vehicle state. Here, for example, a vehicle speed sensor or an acceleration sensor can be suitably used as the vehicle state detection unit.

  According to this aspect, a plurality of predetermined values to be compared with the signal value are stored according to the situation where the vehicle state is different, and the fastening considering the vehicle state is performed by comparing the signal value with the predetermined value according to the vehicle state. The state of the surface can be notified more appropriately.

  The pressure detection unit includes a resistor whose resistance is changed by pressure, and a conduction unit that sandwiches the resistor, and the resistor and the conduction unit are deformed when a surface of the resistor is deformed by pressure. The contact area may be changed.

  According to this aspect, it is possible to achieve a resistor whose resistance changes with pressure with a simple configuration, and to reduce the cost.

  According to the present invention, the pressure of the fastening surface of the disc wheel can be detected.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

(First embodiment)
The pressure detection device according to the present embodiment is sandwiched between the disc wheel and the hub, and can detect the pressure applied to the fastening surface when the disc wheel and the hub are fastened. FIG. 1 is a block diagram illustrating a configuration of a pressure detection device according to the present embodiment. FIG. 2 is a cross-sectional view of the main part of the wheel in a state where the pressure detection unit included in the pressure detection device is sandwiched between the disc wheel and the hub.

(Pressure detection device)
As illustrated in FIG. 1, the pressure detection device 10 includes a pressure detection unit 20, a notification unit 30, and a control unit 40. As shown in FIG. 2, the pressure detection unit 20 is sandwiched between the disc wheel 12 and the hub 14 and detects the pressure applied to the fastening surface when the disc wheel 12 and the hub 14 are fastened. In this embodiment, the disc wheel 12 and the hub 14 are fastened by fixing the plurality of holes 12 a provided in the disc wheel 12 to the plurality of bolts 16 provided in the hub 14 with the through nuts 18. Further, as shown in FIG. 2, the pressure detection unit 20 is connected to a control unit 40 such as an ECU provided outside the disk wheel 12 by a flexible conductive wire 21.

  The alerting | reporting part 30 alert | reports the fastening surface information based on a pressure. For example, the notification unit 30 can be notified to a passenger or the like by using a display device such as a lamp that lights and blinks a lamp, a speaker that emits sound, and a liquid crystal that displays characters and symbols. Here, the fastening surface information is information that the tightening torque of the disc wheel is lower than a predetermined value or higher than a predetermined value, and information that the input of the vehicle weight or the like applied to the axle is excessive. By notifying the passenger and the like of such fastening surface information, it is possible to prompt the re-inspection and maintenance of the tightening torque of the disc wheel and the change to an appropriate load capacity, and the vehicle can be operated more safely.

  The control unit 40 determines the information notified by the notification unit 30 from the pressure detected by the pressure detection unit 20 and controls the notification unit 30. The control unit 40 notifies the notification unit 30 by comparing the signal value S and the predetermined value C with the storage unit 42 that stores the predetermined value C for comparison with the signal value S having a correspondence relationship with the pressure. And an arithmetic unit 44 for discriminating information.

(Pressure detector)
Next, the pressure detector 20 will be described in detail. FIG. 3 is an exploded perspective view of the pressure detection unit. FIG. 4 is a top view of a resistor constituting a part of the pressure detection unit.

  The pressure detection unit 20 includes a resistor 24 having substantially the same shape as the conduction plate 22 between two annular conduction plates 22 to which a conducting wire 21 for connection to the control unit 40 is connected. The conduction plate 22 and the resistor 24 are provided with through holes 22a and 24a through which the bolts 16 provided in the hub 14 pass, as many as the bolts 16. In the present embodiment, five through holes 22 a and 24 a are provided for each of the conduction plate 22 and the resistor 24. Further, five insulating portions 22c and 24c are provided between the adjacent through holes 22a and 24a.

  The conductive plate 22 is a conductor such as metal, and may have a thickness that does not affect when the disc wheel 12 is fastened to the hub 14, and is preferably about 1 mm to several mm. The resistor 24 is made of a material having a higher resistance than the conductive plate 22, and has a material and shape whose resistance is changed by pressure applied when the disc wheel 12 is fastened to the hub 14 via the two conductive plates 22. That's fine.

  In the present embodiment, dimples are provided on the facing surface 24b of the resistor 24 that faces the flat surface 22b of the conductive plate 22, and the flat surface 22b is pressed against the facing surface 24b by pressure, whereby the facing surface 24b and the facing surface 24b are opposed to each other. The contact area with 24b becomes large. As a result, the resistance between the two conductive plates 22 decreases and the current flows easily. Therefore, the resistance of the resistor 24 can be calculated by applying a constant voltage between the two conductive plates 22 and detecting the current flowing at that time. Then, by determining the relationship between the pressure and the resistance at that time, there is a corresponding relationship with the pressure, that is, when the disc wheel 12 is fastened to the hub 14 from the signal value S such as current or voltage that varies depending on the pressure. The pressure generated on the fastening surface can be obtained.

  In the present embodiment, since a plurality of insulating portions 22c and 24c are provided, the resistance of the resistor 24 can be calculated for each of the five regions 24d separated by the insulating portions 22c and 24c. Therefore, it is possible to detect a pressure deviation generated on the fastening surface when the disc wheel 12 is fastened to the hub 14.

  Further, by obtaining the relationship between the state of the predetermined fastening surface and the pressure generated on the fastening surface at that time, the state of various fastening surfaces can be determined and the information can be notified by the notification unit 30. FIG. 5A is a diagram schematically showing the relationship between the tightening torque and the pressure generated on the fastening surface. FIG. 5B is a diagram schematically showing the relationship between the input from the vehicle and the pressure generated on the fastening surface.

  As shown in FIG. 5A, when the tightening torque is increased, the pressure generated on the fastening surface increases. Usually, there is an appropriate range for the tightening torque. If the tightening torque is smaller than the lower limit T1 of the appropriate range, the tightening is loose and the disc wheel is cracked or the tire is likely to be eccentric. Moreover, if it is larger than the upper limit value T2 of the appropriate range, the bolts and nuts are likely to be worn due to excessive tightening. Therefore, it is determined whether or not the disc wheel 12 and the hub 14 are fastened in a range of pressures P1 and P2 corresponding to an appropriate range of the tightening torque, and the result is notified to the occupant or the like. Re-inspection and maintenance can be encouraged.

  Further, as shown in FIG. 5B, the pressure generated on the fastening surface changes due to the difference in the input from the vehicle, for example, due to the difference in the vehicle weight, the load amount, and the road surface condition. Usually, when the vehicle weight or the load capacity increases, the pressure generated on the fastening surface also increases. Therefore, an upper limit value X of the input from the vehicle is determined, and it is determined whether or not the pressure P3 corresponding to the upper limit value X of the input is exceeded on the fastening surface between the disc wheel 12 and the hub 14, and the result is determined by the passenger. For example, it is possible to prompt a change to an appropriate load amount and to operate the vehicle more safely.

(Pressure detection method)
Next, a method for notifying an occupant or the like of the above-described tightening torque and the state of input from the vehicle by detecting the pressure at the fastening surface between the disc wheel 12 and the hub 14 will be described. FIG. 6 is a flowchart when notifying the state of the fastening surface between the disc wheel and the hub in the pressure detection device according to the present embodiment.

  As shown in FIG. 6, the pressure detection device 10 detects a signal value S having a correspondence relationship with the pressure in the pressure detection unit 20 (S11). The signal value S can be detected at a desired timing. Then, the predetermined value C1 having a correspondence relationship with the pressure P1 generated at the lower limit value T1 of the tightening torque described in FIG. 5A is stored in the storage unit 42, and the signal value S is calculated by the calculation unit 44. And a predetermined value C1 are compared (S12).

  Here, when S <C1 (No in S12), the calculation unit 44 determines that the pressure on the fastening surface is equal to or lower than the lower limit pressure P1 of the appropriate range, and the control unit 40 determines that the tightening torque is loose. The notification unit 30 is controlled so as to notify the user (S13). On the other hand, if S ≧ C1 (Yes in S12), the process proceeds to the next step for determining whether the fastening state between the disc wheel 12 and the hub 14 exceeds the upper limit value T2 of the fastening torque.

  Then, the predetermined value C2 having a corresponding relationship with the pressure P2 generated at the upper limit value T2 of the tightening torque described in FIG. 5A is stored in the storage unit 42, and the signal value S is calculated by the calculation unit 44. And a predetermined value C2 are compared (S14).

  Here, when S <C2 (No in S14), the calculation unit 44 determines that the pressure on the fastening surface is in the proper range, and the control unit 40 determines that the notification unit 30 is special because the tightening torque is in the proper range. The control is performed so as to end the detection operation without performing the notification. On the other hand, when S ≧ C2 (Yes in S14), the calculation unit 44 determines that the pressure on the fastening surface is equal to or higher than the upper limit pressure P2 of the appropriate range, and the control unit 40 determines that the tightening torque is excessively tightened. The alerting | reporting part 30 is controlled to alert | report a passenger | crew etc. (S15).

  Further, the process proceeds to the next step in order to determine whether or not the upper limit value X of the input from the vehicle is exceeded on the fastening surface between the disc wheel 12 and the hub 14.

  Here, the predetermined value C3 having a corresponding relationship with the pressure P3 generated at the upper limit value X of the input from the vehicle described in FIG. 5B is stored in the storage unit 42. The signal value S is compared with the predetermined value C3 (S16).

  Here, when S <C3 (No in S16), the calculation unit 44 determines that the pressure is less than the pressure P3 generated at the upper limit value X of the input from the vehicle, and ends the detection operation.

  On the other hand, when S ≧ C3 (Yes in S16), the calculation unit 44 determines that the pressure on the fastening surface is equal to or higher than the pressure P3 corresponding to the upper limit value X of the input allowable value from the vehicle, and the control unit 40 Controls the notification unit 30 to notify the occupant and the like that the input of the vehicle is excessive, for example, that the specified weight is over, such as when the load is excessive or when the occupant is over (S17). .

  Thus, according to the pressure detection device 10, the pressure applied to the fastening surface between the disc wheel 12 and the hub 14 can be detected at a desired timing, and the fastening state between the disc wheel 12 and the hub 14 can be known. it can. Therefore, for example, when the tightening torque of the disc wheel 12 to the hub 14 is not appropriate, or when the load is excessive, it is possible to notify the occupant or the like.

(Second Embodiment)
FIG. 7 is a block diagram illustrating a configuration of a pressure detection device according to the second embodiment. The main point different from the first embodiment is that the pressure detection device 110 further includes a vehicle state detection unit 50 that detects a vehicle state. FIG. 8 is a flowchart when notifying the state of the fastening surface between the disc wheel and the hub in the pressure detection device according to the second embodiment. In the following, portions that overlap with the description of the first embodiment will be omitted as appropriate.

  As the vehicle state detection unit 50, a device that can detect a vehicle state such as a vehicle speed sensor or an acceleration sensor can be suitably used. Thereby, even if the state of the fastening surface changes depending on the vehicle state, the state of the fastening surface in consideration of the vehicle state can be more appropriately notified, and the vehicle can be operated more safely. it can. Below, the vehicle state detection part 50 is a vehicle speed sensor, Comprising: The case where a vehicle state is detected by vehicle speed is demonstrated.

  The control unit 140 stores a plurality of predetermined values (three values of C1, C2, and C3 in the present embodiment) for comparison with the signal value S having a correspondence relationship with the pressure according to the vehicle state. And a calculation unit 144 that discriminates information to be notified by the notification unit 30 by comparing the signal value S and the predetermined value C.

  As shown in FIG. 8, in the pressure detection device 110, the pressure detection unit 20 detects a signal value S having a correspondence relationship with the pressure (S21). Moreover, the vehicle state detection part 50 detects the speed V of the vehicle.

  Next, the vehicle speed V is compared with a reference speed V0 as a threshold value for distinguishing the vehicle state. When the vehicle speed V is equal to or higher than the reference value V0 (Yes in S22), the vehicle state is determined to be a traveling state. In this case, the upper limit value X of the input from the vehicle is set as a predetermined value to be compared with the signal value S in order to determine whether or not the upper limit value X of the input from the vehicle exceeds the fastening surface of the disc wheel 12 and the hub 14. A predetermined value C3 having a corresponding relationship with the pressure P3 generated at this time is selected and compared (S23).

  Here, when S <C3 (No in S23), the calculation unit 144 determines that the pressure is lower than the pressure P3 generated at the upper limit value X of the input from the vehicle, and ends the detection operation.

  On the other hand, when S ≧ C3 (Yes in S23), the calculation unit 144 determines that the pressure on the fastening surface is equal to or higher than the pressure P3 corresponding to the upper limit value X of the allowable input value from the vehicle, and the control unit 140 Controls the notification unit 30 so as to notify the occupant and the like that the input of the vehicle is excessive, for example, that the specified weight is over, such as when the load is excessive or the occupant is over (S24). .

  When the vehicle speed V is less than the reference speed V0 (No in S22), it is determined that the vehicle is low speed or stopped. The value of V0 is not limited to zero, and a value that can be determined even at a low speed of several kilometers per hour may be set. In this case, the pressure generated at the lower limit value T1 of the tightening torque as a predetermined value to be compared with the signal value S in order to determine whether the tightening torque on the fastening surface between the disc wheel 12 and the hub 14 is within an appropriate range. A predetermined value C1 having a corresponding relationship with P1 and a predetermined value C2 having a corresponding relationship with the pressure P2 generated at the time of the upper limit value T2 of the tightening torque are selected and compared (S25, S27).

  Here, when S <C1 (No in S25), the calculation unit 144 determines that the pressure on the fastening surface is equal to or lower than the lower limit pressure P1 of the appropriate range, and the control unit 140 determines that the tightening torque is loose. The notification unit 30 is controlled so as to notify the user (S26). On the other hand, if S ≧ C1 (Yes in S25), the process proceeds to the next step for determining whether the fastening state between the disc wheel 12 and the hub 14 exceeds the upper limit value T2 of the fastening torque.

  Here, when S <C2 (No in S27), the calculation unit 144 determines that the pressure on the fastening surface is in the proper range, and the control unit 40 determines that the notification unit 30 is special because the tightening torque is in the proper range. The control is performed so as to end the detection operation without performing the notification. On the other hand, when S ≧ C2 (Yes in S27), the calculation unit 144 determines that the pressure on the fastening surface is equal to or higher than the upper limit pressure P2 in the appropriate range, and the control unit 140 determines that the tightening torque is excessively tightened. Then, the notification unit 30 is controlled so as to notify a passenger or the like (S28).

  Thus, according to the pressure detection device 110, the pressure applied to the fastening surface between the disc wheel 12 and the hub 14 can be detected at a desired timing, and the fastening state between the disc wheel 12 and the hub 14 is known. be able to. In addition, a plurality of predetermined values to be compared with signal values according to different vehicle states are stored, and the fastening surface state in consideration of the vehicle state by comparing the signal value with a predetermined value according to the vehicle state Can be notified more appropriately. Therefore, for example, when the tightening torque of the disc wheel 12 to the hub 14 is not appropriate or when the loading amount is excessive, the state of the fastening surface can be more appropriately notified to the occupant or the like.

It is a block diagram which shows the structure of the pressure detection apparatus which concerns on 1st Embodiment. It is principal part sectional drawing of the wheel in the state by which the pressure detection part with which a pressure detection apparatus is provided was pinched | interposed between the disc wheel and the hub. It is a disassembled perspective view of a pressure detection part. It is a top view of the resistor which comprises a part of pressure detection part. FIG. 5A is a diagram schematically showing the relationship between the tightening torque and the pressure generated on the fastening surface. FIG. 5B is a diagram schematically showing the relationship between the input from the vehicle and the pressure generated on the fastening surface. It is a flowchart at the time of alerting | reporting the state of the fastening surface of a disc wheel and a hub in the pressure detection apparatus which concerns on 1st Embodiment. It is a block diagram which shows the structure of the pressure detection apparatus which concerns on 2nd Embodiment. It is a flowchart at the time of alerting | reporting the state of the fastening surface of a disc wheel and a hub in the pressure detection apparatus which concerns on 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Pressure detection apparatus, 12 Disc wheel, 14 Hub, 16 bolt, 18 Nut, 20 Pressure detection part, 22 Conduction plate, 22a Through hole, 22c Insulation part, 24 Resistor, 30 Notification part, 40 Control part, 42 Storage part , 44 calculation unit, 50 vehicle state detection unit, 110 pressure detection device, 140 control unit, 142 storage unit, 144 calculation unit.

Claims (5)

  A pressure detection device comprising means for detecting pressure applied to a fastening surface in a state of being clamped between a disc wheel and a hub and fastened to the disc wheel and the hub. A pressure detector that is sandwiched between the disc wheel and the hub and detects the pressure applied to the fastening surface in a state in which the disc wheel and the hub are fastened;
A control unit for determining information of a fastening surface from the pressure;
An informing unit for informing information of the determined fastening surface;
A pressure detection device comprising: The controller is
A storage unit storing a predetermined value for comparison with a signal value having a correspondence relationship with the pressure;
A calculation unit that determines information to be notified by the notification unit by comparing the signal value with the predetermined value;
The pressure detection device according to claim 2, comprising: A vehicle state detector for detecting the vehicle state;
The controller is
A storage unit that stores a plurality of predetermined values according to a detected vehicle state for comparison with a signal value having a correspondence relationship with the pressure,
A calculation unit that determines information to be notified by the notification unit by comparing the signal value and the predetermined value according to a vehicle state;
The pressure detection device according to claim 2, comprising: The pressure detector is
A resistor whose resistance changes with pressure,
A conduction portion for sandwiching the resistor;
Have
5. The pressure detection device according to claim 2, wherein a contact area between the resistor and the conductive portion is changed by deforming a surface of the resistor due to pressure. 6.

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