JP6665068B2 - Gas fuel supply device - Google Patents

Description

  The present invention relates to a gas fuel supply device that uses a linear solenoid to adjust the flow rate of gas fuel supplied from a fuel container to a supply destination.

  As a gas fuel supply device, there is a device using a linear solenoid for adjusting a flow rate of gas fuel supplied from a fuel container to a supply destination. As a linear solenoid used in such a device, for example, there is one described in Patent Document 1. This linear solenoid includes a coil, a fixed core provided in the coil, and a movable core coaxially opposed to the fixed core, and a taper extending toward the movable core at a movable core side end of the fixed core. A first suction portion having a concave shape, and an annular second suction portion provided on the movable iron core side of the first suction portion, the second suction portion being continuous with a side surface of the concave portion. A cylindrical inner peripheral surface is formed. With such a configuration, the linear solenoid described in Patent Literature 1 has a flat suction characteristic that is not affected by the movement displacement (stroke) of the movable core under a constant current, as shown in FIG.

JP 2000-277327 A

  However, when a linear solenoid is used in a gas fuel supply device, the valve opening force required to open the valve increases due to the effect of the gas load of the fuel gas. In particular, in the case of high-pressure gas fuel, the valve opening force increases remarkably. In the gas fuel supply device, since the gas load of the gas fuel acts in the valve opening direction (the spring load acts in the valve closing direction), the suction force Fs generated by the linear solenoid as shown in FIG. When the resultant force F of the gas load Fg and the gas load Fg exceeds the spring load Fk, the gas fuel supply device opens to supply the gas fuel. That is, the gas fuel supply device opens at the valve opening position shown in FIG. The spring load Fk gradually increases until the valve is fully opened after the valve is opened, and the gas load Fg gradually decreases until the valve is fully opened after the valve is opened. Then, the valve opening is fully opened at a position where the maximum value of the spring load Fk (movement displacement of the movable core 100%) and the resultant force F are equal. That is, the gas fuel supply device is fully opened at the fully open position shown in FIG.

  In the above-described linear solenoid, since the attraction force Fs changes in proportion to the current value applied to the coil, if the resultant force F required at the time of opening the valve increases due to the gas load Fg, a small current value It becomes a fully open state by the increase of. As described above, when the above-described linear solenoid is used in a gas fuel supply device, the control range (resolution) of the valve opening in the gas fuel supply device is reduced, and the flow rate control accuracy is deteriorated.

  Therefore, the present invention has been made to solve the above-described problem, and the accuracy of adjusting the flow rate can be improved by expanding the control range of the valve opening degree by the linear solenoid (enhancing the resolution). It is an object to provide a gas fuel supply device.

  One embodiment of the present invention made in order to solve the above problems includes a coil, a fixed core, a movable core attracted to the fixed core by energizing the coil, and a direction in which the movable core is separated from the fixed core. And a linear solenoid having a yoke for covering the coil, and changing the distance between the valve body moving with the movable core and the valve seat fixed to the housing by the linear solenoid. In the gas fuel supply device for adjusting the flow rate of gas fuel, the fixed core has a tapered concave portion at an end on the movable core side, the movable core being movable and narrowing toward the movable core. Wherein the corner of the movable core and the corner of the tapered recess are closest to each other when the valve body is in contact with the valve seat.

  In this gas fuel supply device, when the valve body is in contact with the valve seat, the corner of the movable core and the corner of the tapered concave portion of the fixed core are closest to each other. In the valve position), the axial suction force for axially sucking the movable core can be maximized. The fixed core has a tapered concave portion at an end on the movable core side where the movable core is movable and narrows toward the movable core side. As a result, the gap between the movable core and the fixed core increases as the movable core moves toward the fixed core, so that the suction force of the fixed core sucking the movable core decreases. Therefore, when the value of the current supplied to the coil is constant, the attractive force becomes maximum at the valve opening position (when the valve is opened), and decreases as the movable core moves toward the fixed core.

  Therefore, the increase (slope) of the attraction force with respect to the increase in the current value flowing through the coil can be moderated. It does not become fully open with the increase of the value. That is, the rate of increase in the attraction force with respect to the rate of increase in the current value can be made smaller than in the conventional case. Thereby, the control range of the valve opening degree in the gas fuel supply device by the linear solenoid unit is expanded (the resolution is increased). Therefore, the adjustment accuracy of the flow rate in the gas fuel supply device can be improved.

  Further, another embodiment of the present invention made to solve the above-described problem is a coil, a fixed core, a movable core attracted to the fixed core by energizing the coil, and moving the movable core from the fixed core. A linear solenoid having a spring for urging the coil in a direction away from the coil and a yoke covering the coil, wherein the linear solenoid changes a distance between a valve body moving together with the movable core and a valve seat fixed to the housing. In the gas fuel supply device that adjusts the flow rate of the gas fuel, the movable core includes a tapered portion that increases toward the fixed core at an end of the fixed core, and the fixed core includes the tapered portion. The portion is provided with a movable concave portion, and in a state where the valve body is in contact with the valve seat, a corner portion of the tapered portion and a corner portion of the concave portion are closest to each other. That.

  Also in this gas fuel supply device, when the valve element is in contact with the valve seat, the corner of the tapered portion of the movable core and the corner of the recess of the fixed core are closest to each other. In the valve position), the axial suction force for axially sucking the movable core can be maximized. And the movable core is provided with a tapered part which becomes wider toward the fixed core at the end of the fixed core. As a result, the gap between the movable core and the fixed core increases as the movable core moves toward the fixed core, so that the suction force of the fixed core sucking the movable core decreases. Therefore, when the value of the current supplied to the coil is constant, the attraction force becomes maximum at the valve opening position (when the valve is opened), and decreases as the movable core moves toward the fixed core.

  Therefore, the increase (slope) of the attraction force with respect to the increase in the current value flowing through the coil can be moderated. It does not become fully open with the increase of the value. That is, the rate of increase in the attraction force with respect to the rate of increase in the current value can be made smaller than in the conventional case. Thereby, the control range of the valve opening degree in the gas fuel supply device by the linear solenoid unit is expanded (the resolution is increased). Therefore, the adjustment accuracy of the flow rate in the gas fuel supply device can be improved.

  In the gas supply device described above, the spring constant of the spring is increased within a range not exceeding a force required to move the movable core in the valve opening direction, whereby the movable displacement with respect to the displacement of the movable core is increased. It is preferable that the rate of increase in the spring load by the spring acting on the core approaches the rate of increase in the force required to move the movable core.

  By doing so, the spring load acting on the movable core when the movable displacement of the movable core is maximized (100%), that is, the maximum value of the spring load is increased. At the fully open position, the maximum value of the spring load (the spring load when the moving displacement of the movable core is 100%) is equal to the force (combined force of the suction force and the gas load) required to move the movable core. Therefore, the resultant force at the fully open position increases. Therefore, the moving displacement of the movable core increases. Accordingly, the fully open position can be set at a position farther from the valve opening position, so that the control range of the valve opening in the gas fuel supply device by the linear solenoid unit can be further expanded (resolution can be increased). Therefore, the adjustment accuracy of the flow rate in the gas fuel supply device can be further improved.

  ADVANTAGE OF THE INVENTION According to the gas fuel supply apparatus which concerns on this invention, since the control range of the valve opening degree by a linear solenoid part is expanded (resolution is improved), the adjustment precision of flow rate can be improved.

FIG. 2 is a cross-sectional view of the fuel injection device according to the first embodiment. FIG. 4 is a diagram illustrating a suction force characteristic of a linear solenoid unit according to the first embodiment. FIG. 4 is a diagram illustrating a control range of a valve opening degree in the fuel injection device. It is a sectional view of a fuel injection device in a 2nd embodiment. It is a figure showing the attraction force characteristic of the linear solenoid part in a 2nd embodiment. It is sectional drawing of the fuel injection device in the modification of 2nd Embodiment. FIG. 7 is a diagram illustrating a suction force characteristic of a conventional linear solenoid. FIG. 9 is a diagram illustrating a control range of a valve opening degree in a fuel injection device to which a conventional linear solenoid is applied.

<First embodiment>
In the present embodiment, a case where the gas fuel supply device of the present invention is applied to a fuel injection device (injector) will be described. This fuel injection device is, for example, a device for supplying gaseous fuel (for example, hydrogen) to a fuel cell (not shown) in a fuel cell vehicle. Therefore, the first embodiment will be described first.

  As shown in FIG. 1, the fuel injection device 1 according to the first embodiment includes a linear solenoid unit 10, a valve body 12, a valve seat 14, a housing 16, and the like.

  The linear solenoid unit 10 includes a coil 50, a fixed core 52, a movable core 54, a compression spring 56, bearings 58 and 59, a yoke 60, and the like. The coil 50 is formed by winding a conductive wire around a hollow cylindrical coil bobbin 51. A fixed core 52 and a movable core 54 are arranged in a hollow portion of the coil bobbin 51.

  The fixed core 52 is arranged at one end of the coil bobbin 51. The fixed core 52 is formed in a substantially cylindrical shape (including a true cylindrical shape and an elliptical cylindrical shape), and includes a tapered concave portion 70 and a bearing holding concave portion 74. The tapered recess 70 is formed in a tapered shape in which the movable core 54 is movable and narrows toward the movable core 54, and has a larger diameter than the bearing holding recess 74. The bearing 58 is arranged inside the bearing holding recess 74. The fixed core 52 is formed of a soft magnetic material (for example, electromagnetic stainless steel).

  The movable core 54 is formed in a substantially cylindrical shape (including a true cylindrical shape and an elliptical cylindrical shape), and includes a cylindrical portion 80, a shaft portion 84, and a valve body portion 86. The movable core 54 is formed of a soft magnetic material (for example, electromagnetic stainless steel). In the movable core 54, a part of the cylindrical portion 80 and the valve body 86 are arranged in the housing 16, and the shaft 84 is arranged in the bearing 58. The cylindrical portion 80 and the shaft portion 84 are located inside the hollow portion of the coil bobbin 51. In the movable core 54, when the valve body 12 is in contact with the valve seat 14 (the state shown in FIG. 1), the cylindrical portion corner 81, which is the corner of the cylindrical portion 80, is formed by the tapered recess 70. It is closest to a certain corner 71 of the concave portion.

  The movable core 54 has a shaft 84 at one end slidably supported by the bearing 58, and a valve body 86 slidably supported by the bearing 59 at the other end. As a result, the end of the cylindrical portion 80 of the movable core 54 moves inside the tapered recess 70 on the fixed core 52 side. Further, the valve element 12 is formed integrally with an end of the valve element section 86, and the valve element 12 moves with the movement of the movable core 54.

  The compression spring 56 is disposed inside the bearing 58 and between the fixed core 52 and the movable core 54. The compression spring 56 is in a compressed state and urges the valve body 12 (the movable core 54) toward the valve seat 14. That is, the spring load Fk acts on the movable core 54 in the valve closing direction by the compression spring 56 (see FIG. 3).

  The yoke 60 is arranged so as to surround the coil 50. A lid member 62 is disposed at an opening of the yoke 60. The yoke 60 and the lid member 62 are formed of a soft magnetic material (for example, electromagnetic stainless steel), and constitute a cover of the linear solenoid unit 10.

  The valve element 12 is formed integrally with an end of the valve element section 86 of the movable core 54. The valve element 12 is disposed upstream of the valve seat 14 in the gas fuel flow direction. The valve element 12 includes a substantially disk-shaped seal member 13 on an end surface thereof. This seal member 13 is a portion that comes into contact with / separates from the valve seat 14 (seat portion 15). The seal member 13 is formed of an elastic body such as rubber or resin.

  The valve seat 14 is fixed to a housing 16 and includes a seat portion 15 having an outer side tapered. The sealing member 13 of the valve body 12 abuts on the seat portion 15 while being elastically deformed, so that the sealing performance when the supply of gas fuel is stopped (when the valve is closed) is ensured. The valve seat 14 is disposed downstream of the valve element 12 in the gas fuel flow direction. A discharge hole 22 is formed in the center of the valve seat 14. The discharge hole 22 is a hole that passes through the valve seat 14 in the axial direction, and is a flow path for gas fuel. The discharge hole 22 is connected to a supply destination (for example, a fuel cell) via a fuel pipe.

  The housing 16 is formed in a substantially cylindrical shape, and houses the valve body 12 (part of the movable core 54), the valve seat 14, the bearing 59, and the like. The housing 16 is formed of a soft magnetic material (for example, electromagnetic stainless steel). Further, a fuel passage 18 through which gas fuel flows is formed inside the housing 16. Further, the housing 16 has an inflow hole 20 that communicates with the fuel flow path 18 from the side. The inflow hole 20 is a hole that passes through the housing 16 in the radial direction, and is a gas fuel flow path. The inflow hole 20 is connected to a fuel container (for example, a hydrogen cylinder) via a fuel pipe.

  A part of the housing 16 (a part for accommodating the cylindrical part 80 of the movable core 54) is arranged at the other end of the hollow part of the coil bobbin 51 (on the side opposite to the fixed core 52). An annular member 64 made of a non-magnetic material is arranged between the end of the housing 16 and the end of the fixed core 52.

  Next, the operation (operation) of the fuel injection device 1 will be described. First, when the coil 50 is not energized, that is, when the valve is closed, the sealing member 13 of the valve body 12 is moved by the urging force of the compression spring 56 as shown in FIG. Is in contact with At this time, the gas load Fg of the fuel gas is acting on the movable core 54 in the valve opening direction, but the spring load Fk by the compression spring 56 which is larger than the gas load Fg is acting on the valve closing direction (see FIG. 3). ). Therefore, the discharge hole 22 of the valve seat 14 is shut off from the fuel flow path 18. Therefore, gas fuel is not discharged from the discharge hole 22 to the outside of the fuel injection device 1.

  On the other hand, when the coil 50 is energized, that is, when the valve is opened, magnetic flux flows around the coil 50 through the yoke 60, the housing 16, the movable core 54, the fixed core 52, and the lid member 62, and To form a magnetic circuit. Therefore, a suction force for the fixed core 52 to suction the movable core 54 is generated. The movable core 54 moves toward the fixed core 52 by the suction force. Therefore, the seal member 13 of the valve body 12 is separated from the seat portion 15 of the valve seat 14. Thereby, the discharge hole 22 of the valve seat 14 communicates with the fuel flow path 18.

  Specifically, the discharge hole 22 communicates with the fuel flow path 18 via a gap between the seal member 13 of the valve body 12 and the seat portion 15 of the valve seat 14. Therefore, the gaseous fuel flowing in the fuel flow channel 18 flows into the discharge hole 22 through the gap between the seal member 13 and the seat portion 15. As a result, the gas fuel is discharged from the discharge hole 22 to the outside of the fuel injection device 1. At this time, the amount of movement of the movable core 54 (valve element 12) changes according to the value of the current flowing through the coil 50. Therefore, by controlling the value of the current flowing through the coil 50, the valve opening of the fuel injection device 1 can be adjusted to control the supply amount of gas fuel.

  Here, in the fuel injection device 1, at the start of energization of the coil 50, that is, at the start of valve opening, the cylindrical corner 81 and the concave corner 71 are closest to each other. Thus, when the value of the current supplied to the coil 50 is constant, as shown in FIG. 2, the magnetic attraction generated by the magnetic circuit at the valve opening position is maximized.

  The fixed core 52 has a tapered recess 70 that narrows toward the movable core 54. Therefore, as the movable core 54 moves toward the fixed core 52, the gap between the movable core 54 and the fixed core 52 widens, and the suction force of the fixed core 52 sucking the movable core 54 decreases. Therefore, when the value of the current supplied to the coil 50 is constant, the attractive force becomes maximum at the valve opening position (when the valve is opened), and decreases as the movable core 54 moves to the fixed core 52 side. Has become.

  Therefore, in the fuel injection device 1, as shown in FIG. 3, the increase (gradient) of the attraction force Fs with respect to the increase in the current value becomes gentler than in the conventional example (see FIG. 8). The spring load Fk and the gas load Fg acting on the movable core 54 are the same as in the conventional example. Therefore, during the valve opening operation, the increase (slope) of the resultant force F with respect to the increase in the current value becomes gentler than in the conventional example. That is, the rate of increase of the resultant force F with respect to the rate of increase of the current value can be made smaller than in the conventional example. The resultant force F is a force required to move the movable core 54, and is a resultant force of a suction force Fs for attracting the movable core 54 by the fixed core 52 and a gas load Fg.

  As a result, according to the fuel injection device 1, it is possible to avoid a situation in which the valve is fully opened with a slight increase in the current value after the valve is opened as in the conventional example. As a result, the control range of the valve opening in the fuel injection device 1 by the linear solenoid unit 10 is expanded to twice or more (resolution is increased), and thus the flow rate adjustment accuracy in the fuel injection device 1 is improved.

  Here, by increasing the spring constant of the compression spring 56 within a range that does not exceed the resultant force F required to move the movable core 54 in the valve opening direction, it acts on the movable core 54 with respect to the displacement of the movable core 54. The increase rate of the spring load Fk by the compression spring 56 may be close to the increase rate of the resultant force F required to move the movable core 54. That is, the spring constant of the compression spring 56 may be increased, and the slope of the spring load Fk may be increased so as to approach the resultant force F as indicated by the broken line in FIG.

  By doing so, the spring load Fk acting on the movable core 54 when the stroke of the movable core 54 is maximum (100%), that is, the maximum value of the spring load Fk is increased. Then, the fully open position is a position where the maximum value of the spring load Fk and the resultant force F are equal, so that the resultant force F at the fully open position increases. As a result, the stroke amount of the movable core 54 increases, so that the fully open position can be set to a position further away from the valve opening position. Thereby, the control range of the valve opening of the fuel injection device 1 by the linear solenoid unit 10 can be further expanded (resolution can be increased). Therefore, the adjustment accuracy of the flow rate in the fuel injection device 1 can be further improved.

  As described above in detail, according to the fuel injection device 1 according to the present embodiment, the fixed core 52 includes the tapered recess 70 that narrows toward the movable core 54 at the end on the movable core 54 side. Therefore, the rate of increase in the attraction force with respect to the rate of increase in the current value can be made smaller than in the conventional case. As a result, the control range of the valve opening in the fuel injection device 1 by the linear solenoid unit 10 is expanded (resolution is increased), so that the flow rate adjustment accuracy can be improved.

<Second embodiment>
Next, a second embodiment will be described with reference to FIG. 4, but the same components as those in the first embodiment will be denoted by the same reference numerals, description thereof will be omitted, and different points will be mainly described. .

  In the fuel injection device 101 of the present embodiment, as shown in FIG. 4, the shape of the movable core 154 is different from that of the first embodiment. Specifically, the movable core 154 includes a tapered portion 180 that becomes wider toward the fixed core 52 at the end of the cylindrical portion 80 on the fixed core 52 side. In the state where the valve body 12 is in contact with the valve seat 14 (the state shown in FIG. 4), the movable core 154 is configured such that the tapered portion corner 181 which is the corner of the tapered portion 180 is formed by the concave corner of the fixed core 52. It is closest to 71.

  In such a fuel injection device 101, at the start of energization of the coil 50, that is, at the start of valve opening, the tapered corner 181 and the concave corner 71 are closest to each other. Thus, when the value of the current supplied to the coil 50 is constant, as shown in FIG. 5, the magnetic attraction generated by the magnetic circuit at the valve opening position is maximized.

  The movable core 154 has a tapered portion 180 that is wider toward the fixed core 52 at the end of the cylindrical portion 80 on the fixed core 52 side, and the fixed core 52 has a tapered portion 180 on the movable core 154 side. A tapered recess 70 narrowing toward the bottom is formed. Therefore, as the movable core 154 moves toward the fixed core 52, the gap between the movable core 154 and the fixed core 52 is further widened as compared with the first embodiment. It decreases further than in the first embodiment. Therefore, when the value of the current supplied to the coil 50 is constant, the attraction force becomes maximum at the valve opening position (at the time of valve opening), and as the movable core 154 moves to the fixed core 52 side, the suction force is higher than in the first embodiment. It has a characteristic of greatly decreasing (increase in inclination).

  Therefore, in the fuel injection device 101, the increase (gradient) of the attraction force Fs with respect to the increase in the current value becomes more gentle than in the first embodiment. Therefore, during the valve-opening operation, the increase (slope) of the resultant force F with respect to the increase in the current value becomes more gentle than in the first embodiment. That is, the rate of increase of the resultant force F with respect to the rate of increase of the current value can be made smaller than in the first embodiment.

Therefore, according to the fuel injection device 101, the control range of the valve opening in the fuel injection device 101 by the linear solenoid unit 10 is further expanded (resolution is increased), and thus the flow rate adjustment accuracy in the fuel injection device 101 is further improved. improves.
Further, similarly to the first embodiment, by increasing the spring constant of the compression spring 56 and increasing the inclination of the spring load Fk, the control range of the valve opening in the fuel injection device 101 is further expanded (resolution). Can be increased). As a result, the adjustment accuracy of the flow rate in the fuel injection device 101 can be further improved.

  It should be noted that the above-described embodiment is merely an example, and does not limit the present invention in any way. Needless to say, various improvements and modifications can be made without departing from the gist of the invention. For example, in the second embodiment, the concave portion on the movable core 154 side of the fixed core 52 is a tapered concave portion 70 formed in a tapered shape whose inner diameter gradually changes. However, as shown in FIG. 6, the inner diameter does not change ( The recess 170 may have a constant inner diameter. In this case, since the suction force characteristics are the same as those of the first embodiment, the control range of the valve opening is approximately the same as that of the first embodiment.

  Further, the above-described fuel injection device can be applied to gas fuels other than hydrogen (for example, CNG). Further, in the above-described embodiment, the case where the flow of the gas fuel flows from the inflow hole 20 to the discharge hole 22 through the fuel flow path 18 has been described. The present invention can also be applied to a case where the gas flows to the inflow hole 20 via the passage 18.

DESCRIPTION OF SYMBOLS 1 Fuel injection device 10 Linear solenoid part 12 Valve element 13 Seal member 14 Valve seat 15 Seat part 16 Housing 50 Coil 52 Fixed core 54 Movable core 56 Compression spring 58 Bearing 59 Bearing 60 Yoke 70 Tapered recess 71 Recessed corner 80 Cylindrical section 81 Cylindrical corner

Claims (3)

A linear having a coil, a fixed core, a movable core attracted to the fixed core by energizing the coil, a spring for urging the movable core in a direction away from the fixed core, and a yoke covering the coil A gas fuel supply device comprising a solenoid portion, wherein the linear solenoid portion changes a distance between a valve body that moves together with the movable core and a valve seat fixed to a housing to adjust a flow rate of gas fuel.
The fixed core includes, at an end on the movable core side, a tapered recess in which the movable core is movable and narrows toward the movable core side.
A gas fuel supply device, wherein a corner of the movable core and a corner of the tapered recess are closest to each other when the valve body is in contact with the valve seat. A linear having a coil, a fixed core, a movable core attracted to the fixed core by energizing the coil, a spring for urging the movable core in a direction away from the fixed core, and a yoke covering the coil A gas fuel supply device comprising a solenoid portion, wherein the linear solenoid portion changes a distance between a valve body that moves together with the movable core and a valve seat fixed to a housing to adjust a flow rate of gas fuel.
The movable core includes an end portion on the fixed core side, which includes a tapered portion that increases toward the fixed core side.
The fixed core includes a recess in which the tapered portion is movable,
A gas fuel supply device, wherein a corner of the tapered portion and a corner of the recess are closest to each other when the valve body is in contact with the valve seat. The gas fuel supply device according to claim 1 or 2,
The spring load of the spring acting on the movable core with respect to the displacement of the movable core is increased by increasing the spring constant of the spring within a range not exceeding a force required to move the movable core in the valve opening direction. A gas fuel supply device, wherein the rate of increase of the force is close to the rate of increase of the force required to move the movable core.

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