Patent ID: 12194818

DESCRIPTION OF EMBODIMENTS

A vehicle-mounted device according to embodiments of the present disclosure is described in detail below with reference to the accompanying drawings. In the drawings, the components identical or corresponding to each other are provided with the same reference symbol.

Embodiment 1

A typical example of a vehicle-mounted device installed in a vehicle is a control device for a railway vehicle including a power converter, a circuit breaker, and a transformer, for example. A vehicle-mounted device1according to Embodiment 1 is described below focusing on an exemplary control device installed under the floor of a railway vehicle. As illustrated inFIGS.1and2, the vehicle-mounted device1includes a housing10fixed under the floor of the railway vehicle with fitting members, which are not illustrated, an openable and closable cover11covering an opening10aprovided in the housing10and the circumference of the opening10a, and support members12and15to support the cover11. InFIGS.1and2, the Z axis indicates the vertical direction, the Y axis indicates the direction in which the opening10aextends through the housing10, and the X axis extends in the horizontal direction along the surface provided with the opening10aof the housing10. The X, Y, and Z axes are orthogonal to each other.

The vehicle-mounted device1further includes a sealing member17that surrounds the opening10a, as illustrated inFIG.2. The vehicle-mounted device1also includes a pressure sensor18fixed to an inner surface11bof the cover11at a position such that the pressure sensor18is in contact with the sealing member17while the cover11is closed, as illustrated inFIG.3. The pressure sensor18measures a pressing force received at the sealing member17sandwiched between the housing10and the cover11while the cover11is closed.

When the sealing member17sandwiched between the housing10and the cover11receives a sufficiently large pressing force while the cover11is closed, the sealing member17can prevent the cover11and the housing10from forming a gap therebetween. This configuration can thus inhibit dust, water drops, and the like, from entering the housing10through the opening10a. Unfortunately, when the resilience of the sealing member17decreases due to degradation with age, for example, a reduction occurs in the pressing force received at the sealing member17sandwiched between the housing10and the cover11while the cover11is closed, resulting in formation of a gap between the cover11and the housing10. This gap may allow dust, water drops, and the like, to enter the housing10through the opening10a. In order to solve this problem, the vehicle-mounted device1according to Embodiment 1 further includes a degradation determination device30to determine whether any degradation occurs in the sealing member17on the basis of the pressing force measured at the pressure sensor18while the cover11is closed.

The components of the vehicle-mounted device1are described in detail below.

The housing10accommodates electronic equipment41including a power converter, a circuit breaker, and a transformer, for example. The housing10has the opening10a, as described above, and this opening10aallows maintenance of the electronic equipment41accommodated in the housing10. On the surface of the housing10provided with the opening10a, the support members12, which are described below, are fixed with fastening members13. The surface of the housing10provided with the opening10ahas holes16to engage with the support members15, which are described below.

The cover11has an outer surface11awhich faces the outside of the housing10and on which the support members12are fixed with fastening members14. The cover11supported by the support members12is rotatable about a rotational axis AX and thus openable and closable, as is described in detail below. InFIG.1, the rotational axis AX is represented by the dashed-dotted line. The rotational axis AX extends in the Z-axis direction in Embodiment 1.

The support members12are each fixed to both of the housing10and the outer surface11aof the cover11, and have a hinge structure that supports the cover11such that the cover11is rotatable about the rotational axis AX relative to the housing10. The sections of the support members12fixed to the outer surface11aare rotatable about the rotational axis AX. This structure enables the cover11to rotate about the rotational axis AX, as described above. The vehicle-mounted device1includes two support members12having the identical structure in Embodiment 1.

The support members15, which serve to support the cover11together with the support members12, have a protruding shape and are fixed to the inner surface11bof the cover11, as illustrated inFIG.3. A closing operation of the cover11as illustrated inFIG.1causes the support members15to be inserted into the respective holes16and engage with the holes16. The support members15thus support the cover11while the cover11is closed, and can reduce backlash of the cover11caused by vibration during running of the vehicle in which the vehicle-mounted device1is installed, for example. The vehicle-mounted device1includes two support members15having the identical structure in Embodiment 1.

As illustrated inFIG.4, which is a partial sectional view taken along the line A-A ofFIG.1, the sealing member17has a groove17ato engage with an edge10bof the opening10a. The engagement of the groove17awith the edge10bof the opening10acauses the sealing member17to be fixed to the housing10while surrounding the opening10a. While the cover11is closed, the sealing member17is sandwiched between the housing10and the cover11, as illustrated inFIG.4.

When being pressed, the pressure sensor18outputs a voltage value depending on the pressing force. In other words, the value measured at the pressure sensor18is the voltage value depending on the pressing force. The pressure sensor18is connected to a cable19. The pressure sensor18is supplied with electric power and transmits the measured value to a degradation determination device30via the cable19. The pressure sensor18is preferably supplied with electric power from the electronic equipment41, such as the power converter, accommodated in the housing10.

When the sealing member17is degraded, the sealing member17receives a reduced pressing force from the cover11while the cover11is closed. This force further decreases as the position becomes more distant from the support members12and15. Accordingly, the pressure sensor18is preferably fixed to the housing10at the position most distant from the support members12and15while the cover11is closed. In Embodiment 1, the pressure sensor18is fixed to the inner surface11bof the cover11at a position such that the pressure sensor18is in contact with the center portion of the sealing member17in the X-axis direction in the lower part of the opening10ain the vertical direction.

The degradation determination device30illustrated inFIG.5includes a determiner31to determine whether any degradation occurs in the sealing member17on the basis of the value measured at the pressure sensor18, and a notifier32to output a result of determination at the determiner31. The degradation determination device30is accommodated in the housing10in Embodiment 1.

The determiner31determines whether the voltage value measured at the pressure sensor18is at least a threshold voltage. A voltage value acquired from the pressure sensor18of at least the threshold voltage is deemed to mean that the sealing member17receives a sufficiently large pressing force from the cover11, and no degradation occurs in the sealing member17. In contrast, a voltage value acquired from the pressure sensor18lower than the threshold voltage is deemed to mean that a reduction occurs in the pressing force received at the sealing member17from the cover11due to degradation of the sealing member17. The threshold voltage is defined on the basis of the voltage value measured at the pressure sensor18in the case where the cover11is considered to be certainly closed depending on the air tightness necessary for the vehicle-mounted device1, the material of the sealing member17, and the materials of the housing10and the cover11, for example.

The notifier32outputs a result of determination at the determiner31to, for example, an external apparatus including a display42provided in the cab of the railway vehicle in which the vehicle-mounted device1is installed. In detail, the notifier32provides the display42with a notification indicating whether any degradation occurs in the sealing member17and causes the display42to display the result.

As illustrated inFIG.6, the degradation determination device30is achieved by a processor51, a memory52, and an interface53. The processor51, the memory52, and the interface53are connected to each other via buses50. The processor51is connected to both of the pressure sensor18and the display42via the buses50and the interface53. A process of determining degradation executed at the degradation determination device30is performed by execution of a program stored in the memory52at the processor51. The interface53serves to connect the degradation determination device30to both of the pressure sensor18and the display42and establish communication. The interface53may include multiple types of interfaces, as required. AlthoughFIG.6illustrates an example in which the degradation determination device30includes a single processor51and a single memory52, the degradation determination device30may also include multiple processors51and multiple memories52.

An operation of the degradation determination device30is described below with reference toFIG.7, focusing on an example in which the degradation determination device30operates on the electric power supplied from the electronic equipment41and repeats the process of determining degradation during operation. In this case, an interlock mechanism is preferably provided, for example, so that the electronic equipment41accommodated in the housing10is electrically connected to the power source only when the cover11is closed.

As illustrated inFIG.7, the determiner31acquires a measured value from the pressure sensor18(Step S1). The determiner31then determines whether the voltage value measured at and output from the pressure sensor18is at least the threshold voltage (Step S2). When the determiner31determines that the voltage value acquired from the pressure sensor18is at least the threshold voltage (Step S2; Yes), the above-described steps are repeated from Step S1.

In contrast, when the determiner31determines that the voltage value acquired from the pressure sensor18is lower than the threshold voltage (Step S2; No), the notifier32outputs a result of determination at the determiner31to any external apparatus (Step S3). After Step S3, the above-described steps are repeated from Step S1.

As described above, the vehicle-mounted device1according to Embodiment 1 includes the pressure sensor18fixed to the cover11at a position such that the pressure sensor18is in contact with the sealing member17while the cover11is closed. The pressure sensor18outputs a voltage value depending on the pressing force received at the sealing member17sandwiched between the housing10and the cover11while the cover11is closed. The degradation determination device30then determines whether the voltage value is at least the threshold voltage and outputs a determination result. A voltage value of at least the threshold voltage is deemed to mean that the sealing member17sandwiched between the housing10and the cover11receives a sufficiently large pressing force, and no degradation occurs in the sealing member17. In contrast, a voltage value lower than the threshold voltage is deemed to mean that the sealing member17sandwiched between the housing10and the cover11receives a small pressing force, and any degradation occurs in the sealing member17. The vehicle-mounted device1can thus determine degradation of the sealing member17on the basis of the value measured at the pressure sensor18. The vehicle-mounted device1can therefore maintain the waterproofness and dust resistance. In detail, the determination of degradation of the sealing member17can lead to facilitation of a maintenance operation including replacement of the sealing member17in the case of degradation of the sealing member17, and prevention of the degraded sealing member17from allowing dust, water drops, and the like, to enter the vehicle-mounted device1.

Since the threshold voltage is defined as a voltage value that can achieve the air tightness necessary for the housing10of the vehicle-mounted device1, degradation of the sealing member17can be determined at the stage before the housing10loses the required air tightness. This configuration can thus facilitate a maintenance operation including replacement of the sealing member17before the housing10loses the required air tightness.

Embodiment 2

The sealing member17may also be fixed to the cover11. Embodiment 2 is directed to a vehicle-mounted device2including a sealing member21fixed to the cover11.

The vehicle-mounted device2illustrated inFIG.8differs from the vehicle-mounted device1according to Embodiment 1, in that the vehicle-mounted device2includes a first protruding member20that surrounds the opening10aof the housing10and extends toward the outside of the housing10, and the sealing member21fixed to the inner surface11bof the cover11at a position such that the sealing member21is in contact with the first protruding member20while the cover11is closed, as illustrated inFIG.9.

As illustrated inFIGS.8and10, the first protruding member20is made of a member having a shape of bent plate. The first protruding member20is fixed around the opening10aof the housing10with fastening members, which are not illustrated, and extends in the direction apart from the housing10, that is, toward the negative side in the Y-axis direction.

As illustrated inFIG.9, the sealing member21is fixed to the inner surface11bof the cover11with an adhesive, for example. The sealing member21is fixed to the inner surface11bof the cover11at a position such that the sealing member21is in contact with the first protruding member20while the cover11is closed, as illustrated inFIG.10.

In the vehicle-mounted device2, the pressure sensor18is fixed to at least one of the inner surface11bor the sealing member21at a position such that the pressure sensor18faces a part of the first protruding member20with the sealing member21arranged therebetween while the cover11is closed. The pressure sensor18measures a pressing force received at the sealing member21sandwiched between the housing10and the cover11, as in Embodiment 1. In detail, the pressure sensor18measures a pressing force applied to the sealing member21sandwiched between the first protruding member20fixed to the housing10and the cover11.

As in Embodiment 1, when the sealing member21is degraded, the sealing member21sandwiched between the housing10and the cover11receives a reduced pressing force while the cover11is closed. This force further decreases as the position becomes more distant from the support members12and15. Accordingly, the pressure sensor18is preferably fixed to at least one of the cover11or the sealing member21at the position most distant from the support members12and15while the cover11is closed. In Embodiment 2, the pressure sensor18is fixed to at least one of the inner surface11bof the cover11or the sealing member21at a position such that the pressure sensor18is in contact with the center portion of the sealing member21in the X-axis direction in the lower portion of the cover11in the vertical direction.

The degradation determination device30according to Embodiment 2 has the structure and operation identical to those in Embodiment 1. The degradation determination device30according to Embodiment 2 can determine whether any degradation occurs in the sealing member21on the basis of the value measured at the pressure sensor18.

As described above, the vehicle-mounted device2according to Embodiment 2 includes the pressure sensor18fixed to at least one of the cover11or the sealing member21at a position such that the pressure sensor18faces the first protruding member20fixed to the housing10with the sealing member21arranged therebetween while the cover11is closed. The pressure sensor18outputs a voltage value depending on the pressing force received at the sealing member21sandwiched between the housing10and the cover11. The degradation determination device30then determines whether the voltage value is at least the threshold voltage and outputs a determination result. A voltage value of at least the threshold voltage is deemed to mean that the sealing member21sandwiched between the housing10and the cover11receives a sufficiently large pressing force, and no degradation occurs in the sealing member21. In contrast, a voltage value lower than the threshold voltage is deemed to mean that the sealing member21sandwiched between the housing10and the cover11receives a small pressing force, and any degradation occurs in the sealing member21. The vehicle-mounted device2can thus determine degradation of the sealing member21on the basis of the value measured at the pressure sensor18. The vehicle-mounted device2can therefore maintain the waterproofness and dust resistance.

Embodiment 3

The pressure sensor18may also be fixed to the housing10. Embodiment 3 is directed to a vehicle-mounted device3including the pressure sensor18fixed to the housing10.

The vehicle-mounted device3illustrated inFIG.11differs from the vehicle-mounted device1according to Embodiment 1, in that the vehicle-mounted device3includes a sealing member22held by a retainer23provided to the housing10, and a second protruding member24fixed to the inner surface11bof the cover11at a position such that the second protruding member24is in contact with the sealing member22while the cover11is closed, as illustrated inFIG.12.

As illustrated inFIG.11, the sealing member22is held by the retainer23provided around the opening10aof the housing10and is fixed to the housing10.

As illustrated inFIG.13, the retainer23extends in the direction apart from the housing10and holds the sealing member22therein. In detail, the retainer23surrounds the opening10aand is made of two plate segments spaced from each other.

The second protruding member24is made of a member having a shape of bent plate, as illustrated inFIGS.12and13. The second protruding member24is fixed to the inner surface11bof the cover11with fastening members, which are not illustrated, and extends in the direction apart from the inner surface11b.

In the vehicle-mounted device3, the pressure sensor18is fixed to at least one of the housing10or the sealing member22at a position such that the pressure sensor18faces a part of the second protruding member24with the sealing member22arranged therebetween while the cover11is closed. In detail, the pressure sensor18is fixed to at least one of the housing10or the sealing member22at a position such that the pressure sensor18is held by the retainer23. The pressure sensor18measures a pressing force received at the sealing member22sandwiched between the housing10and the cover11, as in Embodiments 1 and 2. In detail, the pressure sensor18measures a pressing force applied to the sealing member22sandwiched between the housing10and the second protruding member24fixed to the cover11.

As in Embodiments 1 and 2, when the sealing member22is degraded, the sealing member22sandwiched between the housing10and the cover11receives a reduced pressing force while the cover11is closed. This force further decreases as the position becomes more distant from the support members12and15. Accordingly, the pressure sensor18is preferably fixed to at least one of the housing10or the sealing member22at the position most distant from the support members12and15while the cover11is closed. In Embodiment 3, the pressure sensor18is fixed to at least one of the housing10or the sealing member22at a position such that the pressure sensor18is in contact with the center portion of the sealing member22in the X-axis direction in the lower portion of the opening10ain the vertical direction.

The degradation determination device30according to Embodiment 3 has the structure and operation identical to those in Embodiment 1. The degradation determination device30according to Embodiment 3 can determine whether any deterioration occurs in the sealing member22on the basis of the value measured at the pressure sensor18.

As described above, the vehicle-mounted device3according to Embodiment 3 includes the pressure sensor18fixed to at least one of the housing10or the sealing member22at a position such that the pressure sensor18faces the second protruding member24fixed to the cover11with the sealing member22arranged therebetween while the cover11is closed. The pressure sensor18outputs a voltage value depending on the pressing force received at the sealing member22sandwiched between the housing10and the cover11. The degradation determination device30then determines whether the voltage value is at least the threshold voltage and outputs a determination result. A voltage value of at least the threshold voltage is deemed to mean that the sealing member22sandwiched between the housing10and the cover11receives a sufficiently large pressing force, and no degradation occurs in the sealing member22. In contrast, a voltage value lower than the threshold voltage is deemed to mean that the sealing member22sandwiched between the housing10and the cover11receives a small pressing force, and any degradation occurs in the sealing member22. The vehicle-mounted device3can thus determine degradation of the sealing member22on the basis of the value measured at the pressure sensor18. The vehicle-mounted device3can therefore maintain the waterproofness and dust resistance.

The above-described embodiments of the present disclosure are not intended to limit the scope of the present disclosure. The above-described hardware configurations and flowchart are mere examples and may be arbitrarily varied and modified.

The operation of the degradation determination device30in the above-described embodiments is a mere example. In the case where any of the vehicle-mounted devices1to3is installed in a railway vehicle, the pressing force applied to the pressure sensor18fluctuates, for example, while the railway vehicle is running through a tunnel or passing by another railway vehicle. In order to inhibit this fluctuation from leading to an error in determination of deterioration of the sealing member17,21, or22, the degradation determination device30included in any of the vehicle-mounted devices1to3may determine whether the period during which the value measured at the pressure sensor18has been lower than the threshold value is equal to or longer than a predetermined period. The predetermined period is a period long enough not to mistake the above-described fluctuation of the pressing force for degradation of the sealing member17,21, or22. For example, the predetermined period has a duration of approximately several tens of seconds.

A modification of the operation of the degradation determination device30designed so as not to mistake the fluctuation of the pressing force for degradation of the sealing member17,21, or22, as described above, is described below with reference toFIG.14. Steps S1and S2inFIG.14correspond to Steps S1and S2inFIG.7.

When the determiner31determines that the voltage value acquired from the pressure sensor18is lower than the threshold voltage (Step S2; Yes), the notifier32determines whether the period during which the determiner31has been determining the voltage value to be lower than the threshold voltage is equal to or longer than the predetermined period (Step S21). In detail, the notifier32acquires a determination result from the determiner31, and causes the result to be stored into a memory, which is not illustrated, in association with a time acquired from a timer. On the basis of the determination results that have been stored into the memory for the latest predetermined period, the notifier32determines whether the period during which the determiner31has been determining the voltage value to be lower than the threshold voltage is equal to or longer than the predetermined period. The predetermined period is a period long enough not to mistake the fluctuation of the pressing force for degradation of the sealing member17,21, or22, as described above.

When the notifier32determines that the period during which the determiner31has been determining the voltage value to be lower than the threshold voltage is shorter than the predetermined period (Step S21; No), the above-described steps are repeated from Step S1. When the period during which the determiner31has been determining the voltage value to be lower than the threshold voltage is shorter than the predetermined period, this situation is deemed to mean that the fluctuation of the value measured at the pressure sensor18is just a temporary variation, and no degradation occurs in the sealing member17,21, or22. In detail, when at least one of the determination results that have been stored into the memory for the latest predetermined period indicates a voltage value of at least the threshold voltage, the period during which the determiner31has been determining the voltage value to be lower than the threshold voltage is considered to be shorter than the predetermined period.

In contrast, when the notifier32determines that the period during which the determiner31has been determining the voltage value to be lower than the threshold voltage is equal to or longer than the predetermined period (Step S21; Yes), the notifier32outputs a result of determination at the determiner31to the display42(Step S3). In detail, when all the determination results that have been stored into the memory for the latest predetermined period indicate voltage values lower than the threshold voltage, the period during which the determiner31has been determining the voltage value to be lower than the threshold voltage is considered to be equal to or longer than the predetermined period. Step S3corresponds to Step S3inFIG.7.

As described above, the degradation determination device30provides a notification indicating occurrence of degradation of the sealing member17,21, or22when the period during which the value measured at the pressure sensor18has been lower than the threshold voltage is equal to or longer than the predetermined period. This configuration can improve the accuracy of determination of degradation of the sealing member17,21, or22.

Any of the vehicle-mounted devices1to3may include multiple pressure sensors18disposed at mutually different positions. In this case, the determiner31may determine whether each of the voltage values measured at the individual pressure sensors18is at least a threshold voltage. The voltage values measured at the pressure sensors18may be compared with the same threshold voltage or mutually different threshold voltages. In the case of different threshold voltages for the individual pressure sensors18, these threshold voltages may be defined depending on the positions of the individual pressure sensors18, for example. In detail, the threshold voltages for the individual pressure sensors18may be defined depending on the distances from the support members12and15to the individual pressure sensors18. When the determiner31determines that a voltage value measured at at least one of the multiple pressure sensors18is lower than the threshold voltage, the notifier32may output a result of determination at the determiner31to the display42.

The numbers and positions of the support members12and15included in any of the vehicle-mounted devices1to3may be arbitrarily defined depending on the properties, such as material and weight, of the cover11. For example, the support members12may be fixed to both of the housing10and the cover11such that the rotational axis AX extends in the X-axis direction. In this case, parts of the support members12may be fixed to the upper portion of the opening10ain the Z-axis direction, while the other parts of the support members12may be fixed to the outer surface11aof the cover11.

The opening10amay also be provided in the upper or lower surface of the housing10in the vertical direction, as well as the side surface of the housing10.

The support members12may also be fixed by any means, as well as being fixed with the fastening members13and14. For example, the support members12may be fixed to both of the housing10and the cover11with an adhesive or by welding.

The support members12may also have any structure for supporting the cover11such that the cover11is rotatable about the rotational axis AX, as well as the hinge structure.

The support members15may also have any shape provided that the support members15can support the cover11while the cover11is closed and reduce backlash of the cover11caused by vibration during running of the vehicle in which any of the vehicle-mounted devices1to3is installed, as well as the shape of protrusion provided on the inner surface11bof the cover11. For example, the support members15may also be protrusions provided on the housing10. In this case, the cover11may be provided with members to engage with the support members15.

The support members15may be fabricated separately from the cover11, fixed to the cover11, or integrated with the cover11.

The pressure sensor18may be supplied with electric power from the electronic equipment accommodated in the housing10as in Embodiments 1 to 3 described above, or may include an internal power source.

The first protruding member20may also be fixed to the housing10by any means, and the second protruding member24may also be fixed to the cover11by any means, as well as being fixed with the fastening members. For example, the first protruding member20may be fixed to the housing10and the second protruding member24may be fixed to the cover11with an adhesive or by welding. The first protruding member20may also be integrated with the cover11. The second protruding member24may also be integrated with the housing10.

The degradation determination device30may be provided outside the housing10. In this case, the degradation determination device30may determine whether the vehicle is running on the basis of information from an activation switch or a control system for the vehicle, for example, and then determine whether the voltage value acquired from the pressure sensor18is at least the threshold voltage during running of the vehicle.

The degradation determination device30is not required to be provided in the vehicle in which any of the vehicle-mounted devices1to3is installed. In this case, the degradation determination device30may acquire a value measured at the pressure sensor18via a network inside the vehicle and a network for connecting devices inside the vehicle to devices outside the vehicle. The degradation determination device30may also be achieved in the form of a function of the control system for the vehicle.

The vehicle-mounted devices1to3may also be installed in other vehicles, such as automobiles, marine vessels, and aircrafts, as well as railway vehicles. The vehicle-mounted devices1to3may also be provided at any site, such as on the floor or on the roof, as well as under the floor.

The foregoing describes some example embodiments for explanatory purposes. Although the foregoing discussion has presented specific embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the broader spirit and scope of the invention. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. This detailed description, therefore, is not to be taken in a limiting sense, and the scope of the invention is defined only by the included claims, along with the full range of equivalents to which such claims are entitled.

REFERENCE SIGNS LIST

1,2,3Vehicle-mounted device10Housing10aOpening10bEdge11Cover11aOuter surface11bInner surface12,15Support member13,14Fastening member16Hole17,21,22Sealing member17aGroove18Pressure sensor19Cable20First protruding member23Retainer24Second protruding member30Degradation determination device31Determiner32Notifier41Electronic equipment42Display50Bus51Processor52Memory53InterfaceAX Rotational axis