JP5500389B2 - Stroke amount detection device - Google Patents

Description

  The present invention relates to a stroke amount detection device that detects a relative stroke amount to be detected.

  Conventionally, a magnet as a magnetic field generating means, and a magnetic detection element that detects a change in the magnetic field by moving relative to the magnet along with the linear movement of the detection target, and based on the output signal of the magnetic detection element, 2. Description of the Related Art A stroke amount detection device that detects a relative stroke amount is known. For example, in the stroke amount detection device described in Patent Document 1, four magnets sandwiching a magnetic detection element are arranged.

JP 2008-45919 A

By the way, in the stroke amount detection apparatus described above, the arrangement of the four magnets increases the size of the magnetic circuit and increases the cost.
The present invention has been made in view of the above points, and an object of the present invention is to provide a stroke amount detection device capable of reducing the number of magnets and miniaturizing a magnetic circuit.

  A stroke amount detection device according to claim 1 of the present invention detects a relative stroke amount of a detection target that moves linearly, and includes a first magnetic field generation unit, a second magnetic field generation unit, and a magnetic detection unit. . The first magnetic field generating means and the second magnetic field generating means are arranged to face each other in the stroke direction, are magnetized so that the opposing magnetic poles are the same polarity, and move along with the linear movement of the detection target. . The magnetic detection means is provided with a magnetosensitive surface substantially orthogonal to the stroke direction, and a virtual axis passing through the first magnetic field generating means and the second magnetic field generating means along the stroke direction or a virtual axis parallel to the virtual axis. It moves relative to the first magnetic field generating means and the second magnetic field generating means on a straight line, and changes in the magnetic field due to the movement of the first magnetic field generating means and the second magnetic field generating means are detected.

  The first magnetic field generating means and the second magnetic field generating means are magnetized so that the magnetic poles facing each other in the stroke direction have the same polarity. For this reason, repulsion of the magnetic flux occurs between the first magnetic field generating means and the second magnetic field generating means, and the magnetic flux vector changes along the stroke direction between the first magnetic field generating means and the second magnetic field generating means. . Therefore, the relative stroke amount based on the change of the magnetic flux vector can be detected by the magnetic detection means provided between the first magnetic field generation means and the second magnetic field generation means. Here, the stroke amount detection device requires only two magnetic field generating means as compared with the prior art, and the magnetic circuit can be made compact. Further, since the first magnetic field generating means and the second magnetic field generating means are arranged to face each other in the stroke direction, by adjusting the distance between the first magnetic field generating means and the second magnetic field generating means, The detection range of the relative stroke amount can be adjusted.

Moreover, it further has a 1st magnetic flux transmission means which connects the opposite magnetic poles of the 1st magnetic field generation means and the 2nd magnetic field generation means opposite.
Thereby , the leakage of the magnetic flux of a 1st magnetic field generation means and a 2nd magnetic field generation means can be suppressed, and the permeance of a magnetic circuit can be improved. Therefore, the magnetic flux density detected by the magnetic detection element can be increased and the SN ratio can be improved. In addition, due to the shielding effect, it is possible to improve the robustness against the magnetic field on the opposite side of the first magnetic field generating unit and the second magnetic field generating unit with respect to the first magnetic flux transmitting unit and the disturbance magnetic field due to the proximity of the magnetic substance.

Further , the first magnetic flux transmission means has a first convex portion that protrudes toward the imaginary axis at the intermediate portion in the stroke direction.
Thereby, the space | gap of the intermediate part of a 1st magnetic flux transmission means becomes narrow, and a magnetic flux density can be raised. For this reason, it is possible to increase the sensitivity of the magnetic detection element passing through the virtual axis side of the intermediate portion of the first magnetic flux transmission means. Therefore, the linearity of the detected magnetic flux density detected by the magnetic detection element can be improved.

According to the second aspect of the present invention, the second magnetic flux transmission means is further provided on the side opposite to the intermediate portion of the first magnetic flux transmission means with respect to the virtual axis. Here, a 2nd magnetic flux transmission means is connected to the end of the direction orthogonal to the virtual axis of the intermediate part of a 1st magnetic flux transmission means.
As a result, the gap is further narrowed compared to the stroke amount detection device according to claim 1 , the magnetic flux density on the virtual axis side of the intermediate portion of the first magnetic flux transmission means can be further increased, and the middle of the first magnetic flux transmission means The sensitivity of the magnetic detection element passing through the virtual axis side of the part can be further increased. Therefore, the linearity of the detected magnetic flux density detected by the magnetic detection element can be further improved.

According to the invention which concerns on Claim 3, it is further provided with a 2nd magnetic flux transmission means on the opposite side to a 1st magnetic flux transmission means with respect to a virtual axis. Here, the second magnetic flux transmission means connects the magnetic poles on the opposite side to the opposing magnetic poles of the first magnetic field generating means and the second magnetic field generating means.
Thus, the first magnetic field generating means and the second magnetic field generating means are surrounded by the first magnetic flux transmitting means and the second magnetic flux transmitting means, and are more resistant to the disturbance magnetic field than the stroke amount detecting device according to claim 1 or 2 . Robustness can be further increased.

According to the invention which concerns on Claim 4 , a 2nd magnetic flux transmission means has the 2nd convex part which protrudes in the intermediate part of a stroke direction at the virtual axis side.
Thereby, the magnetic flux density by the side of the virtual axis of the intermediate part of the 2nd magnetic flux transmission means can be raised. For this reason, the sensitivity of the magnetic detection element passing through the virtual axis side of the intermediate portion of the second magnetic flux transmission means can be increased. Therefore, compared with the stroke amount detecting apparatus according to claim 1, it is possible to improve the linearity of the detected magnetic flux density detected by the magnetic detecting element.

According to the invention which concerns on Claim 5 , the 1st magnetic flux transmission means and the 2nd magnetic flux transmission means are symmetrically arranged with respect to the virtual axis.
Thereby, the balance of arrangement | positioning of a 1st magnetic flux transmission means and a 2nd magnetic flux transmission means can be improved.

According to the invention which concerns on Claim 6 , a 1st magnetic flux transmission means and a 2nd magnetic flux transmission means are symmetrical shapes with respect to the reference plane equidistant from a 1st magnetic field generation means and a 2nd magnetic field generation means.
Thereby, the balance of arrangement | positioning of a 1st magnetic flux transmission means and a 2nd magnetic flux transmission means can be improved more.

According to the seventh aspect of the present invention, the first magnetic field generating means and the second magnetic field generating means have the same magnetic characteristics, and are equidistant from the first magnetic field generating means and the second magnetic field generating means. Symmetrical arrangement.
Thereby, the position where the relative stroke amount is 0 can be set to the position where the magnetic flux density is 0. Since the magnetic field at the position where the magnetic flux density is 0 is not easily affected by a change in temperature, the detection accuracy at the zero point of the relative stroke amount of the magnetic detection means can be improved.

According to the invention of claim 8 , the first magnetic field generating means and the second magnetic field generating means have different sizes.
Thereby, the position where the relative stroke amount is 0 can be set to a position other than the position where the magnetic flux density is 0. For this reason, the detection accuracy on the right side or the left side of the position where the relative stroke amount is 0 can be particularly improved as compared with the position where the relative stroke amount is 0.

According to the invention of claim 9 , the magnetic detection means moves relative to the first magnetic field generation means and the second magnetic field generation means on the virtual axis.
Thereby, the detection accuracy of a magnetic detection element can be improved.

According to the invention of claim 1 0, the magnetic detection means, with respect to the first magnetic field generating means and second magnetic field generating means, in parallel to the imaginary axis, and relatively moves the different virtual straight line and the virtual axis.
Thereby, it is possible to cope with different mounting variations of the first magnetic field generating means, the second magnetic field generating means, and the magnetic detection element.

(A) The schematic diagram which shows the stroke amount detection apparatus by 1st Embodiment of this invention. (B) The characteristic view of the detection magnetic flux density of the Hall element by 1st Embodiment of this invention. 1 is a block diagram showing the overall configuration of a system to which a stroke amount detection device according to a first embodiment of the present invention is applied. (A) The schematic diagram which shows the stroke amount detection apparatus by 2nd Embodiment of this invention, (B) The characteristic figure of the detected magnetic flux density of the Hall element by 2nd Embodiment of this invention. (A) The schematic diagram which shows the stroke amount detection apparatus by 3rd Embodiment of this invention, (B) The characteristic figure of the detected magnetic flux density of the Hall element by 3rd Embodiment of this invention. The schematic diagram which shows the stroke amount detection apparatus by 4th Embodiment of this invention. (A) The schematic diagram which shows the stroke amount detection apparatus by 5th Embodiment of this invention, (B) The characteristic view of the detected magnetic flux density of the Hall element by 5th Embodiment of this invention. The VII direction view side view of FIG. 6 (A). (A) The schematic diagram which shows the stroke amount detection apparatus by 6th Embodiment of this invention, (B) The characteristic figure of the detected magnetic flux density of the Hall element by 6th Embodiment of this invention. (A) The schematic diagram which shows the stroke amount detection apparatus by 7th Embodiment of this invention, (B) The characteristic figure of the detected magnetic flux density of the Hall element by 7th Embodiment of this invention. (A) The schematic diagram which shows the stroke amount detection apparatus by 8th Embodiment of this invention, (B) The characteristic figure of the detected magnetic flux density of the Hall element by 8th Embodiment of this invention. The schematic diagram which shows the stroke amount detection apparatus by 9th Embodiment of this invention. The schematic diagram which shows the stroke amount detection apparatus by 10th Embodiment of this invention. The schematic diagram which shows the stroke amount detection apparatus by 11th Embodiment of this invention. (A) The schematic diagram which shows the stroke amount detection apparatus by 12th Embodiment of this invention, (B) The characteristic figure of the detected magnetic flux density of the Hall element by 12th Embodiment of this invention. (A) The schematic diagram which shows the stroke amount detection apparatus by 12th Embodiment of this invention, (B) The characteristic figure of the detected magnetic flux density of the Hall element by 12th Embodiment of this invention. (A) The schematic diagram which shows the stroke amount detection apparatus by 13th Embodiment of this invention, (B) The characteristic figure of the detected magnetic flux density of the Hall element by 13th Embodiment of this invention. (A) The schematic diagram which shows the stroke amount detection apparatus by 13th Embodiment of this invention, (B) The characteristic figure of the detected magnetic flux density of the Hall element by 13th Embodiment of this invention.

Hereinafter, a stroke amount detection device according to an embodiment of the present invention will be described with reference to the drawings.
(First embodiment)
The stroke amount detection device of the present invention is a device that detects a relative stroke amount to be detected by being applied to a stroke portion of a transmission, an accelerator, a brake or the like of an automobile, for example.

  As shown in FIG. 2, the stroke amount detection device 1 includes a first magnet 21 as a first magnetic field generation unit, a second magnet 22 as a second magnetic field generation unit, and a Hall element 51 as a magnetic detection unit. ing. The first magnet 21 and the second magnet 22 move relative to the Hall element 51 with the linear movement of the stroke portion 61 of the linear actuator 60, and detect the relative stroke amount. The detected relative stroke amount is output to an ECU (engine control unit) 100. The ECU 100 feedback-controls the linear actuator 60 based on the relative stroke amount output from the stroke amount detection device 1.

The configuration of the stroke amount detection device 1 will be described with reference to FIG. 1 (A) and FIG.
As shown in FIG. 1A, the stroke amount detection device 1 includes a first magnet 21, a second magnet 22, and a hall element 51. The first magnet 21 and the second magnet 22 have the same shape and magnetic characteristics, and are formed in a substantially rectangular parallelepiped. As shown in FIG. 2, the first magnet 21 and the second magnet 22 are provided in a stroke portion 61 that moves linearly and move together with the stroke portion 61. In the present embodiment, the first magnet 21 and the second magnet 22 are provided so that the N poles face each other along the moving direction of the stroke portion 61. Hereinafter, the moving direction of the stroke part 61 is referred to as “X direction”, and the direction orthogonal to the X direction is referred to as “Y direction”. A line connecting the midpoint of the first magnet 21 in the Y direction and the midpoint of the second magnet 22 in the Y direction is defined as a “horizontal axis X”, and the first magnet 21 and the second magnet 22 along the Y direction A line passing through the middle point O is defined as “vertical axis Y”. In the present embodiment, the movement range of the stroke portion 61 is L. Here, the horizontal axis X corresponds to the “virtual axis” in the claims.

  The hall element 51 is fixed on the horizontal axis X between the first magnet 21 and the second magnet 22, and is provided so that the magnetosensitive surface 511 is orthogonal to the X direction. The hall element 51 is mounted on the hall IC chip 50.

  When the first magnet 21 and the second magnet 22 move relative to the Hall element 51 as the stroke portion 61 moves linearly, the magnetic flux density detected by the magnetic sensitive surface 511 is as shown in FIG. Change. Hereinafter, the first magnet 21 side is referred to as “left side”, and the second magnet 22 side is referred to as “right side”.

  In the present embodiment, when the position of the Hall element 51 coincides with the middle point O, the detected relative stroke amount is set to zero. The relative stroke amount when the first magnet 21 and the second magnet 22 move to the left side with respect to the Hall element 51 is expressed as a positive value, and the first magnet 21 and the second magnet 22 move to the right side with respect to the Hall element 51. The relative stroke amount is expressed as a negative value.

  Further, as the direction of the magnetic flux vector detected by the Hall element 51, the direction from left to right in the X direction is negative, and the direction from right to left is positive. Therefore, in this embodiment, the magnetic flux density detected on the right side of the Hall element 51 is a positive value, and the magnetic flux density detected on the left side is a negative value. Here, if the maximum magnetic flux density detected by the Hall element 51 within the movement range L of the stroke portion 61 is + B, the minimum magnetic flux density detected by the Hall element 51 is −B (see FIG. 1B). ).

Hereinafter, the effect of this embodiment will be described.
In the present embodiment, the first magnet 21 and the second magnet 22 are arranged along the stroke direction so that the N poles face each other. For this reason, the magnetic flux vector between the 1st magnet 21 and the 2nd magnet 22 changes along a stroke direction. Therefore, the change in the magnetic flux vector can be detected by the Hall element 51 provided between the first magnet 21 and the second magnet 22. Here, since the stroke amount detection device 1 of the present embodiment requires only two of the first magnet 21 and the second magnet 22 as magnetism generating means, the magnetic circuit can be made compact. The first magnet 21 and the second magnet 22 are arranged to face each other in the stroke direction. For this reason, the detection range of the relative stroke amount can be adjusted by adjusting the distance between the first magnet 21 and the second magnet 22.

  In the present embodiment, the first magnet 21 and the second magnet 22 are disposed symmetrically with respect to a reference plane that is orthogonal to the horizontal axis X and includes the vertical axis Y. Thereby, the position where the magnetic flux density with high detection accuracy is 0 can be set at the point where the relative stroke amount of the Hall element 51 is 0.

  In this embodiment, since the 1st magnet 21 and the 2nd magnet 22 are a rectangular parallelepiped simple shape, the dispersion | variation in a process and an assembly process can be suppressed. Moreover, since it is a simple shape, manufacturing cost can be reduced.

(Second Embodiment)
A stroke amount detection device according to a second embodiment of the present invention is shown in FIG. In addition, the same code | symbol is attached | subjected to the site | part substantially the same as 1st Embodiment, and description is abbreviate | omitted.
As shown in FIG. 3A, the stroke amount detection device 2 of the present embodiment includes a first magnet 21, a second magnet 22, a Hall element 51, and a first yoke 32 as a first magnetic flux transmission means. ing.

  The first yoke 32 is formed of a magnetic material such as a steel material, and has a U-shaped cross section including a first wall 321, a second wall 322, and a third wall 323 that connects the first wall 321 and the second wall 322. It is a frame shape. The end of the first wall 321 opposite to the third wall 323 is connected to the S pole of the first magnet 21. The end of the second wall 322 opposite to the third wall 323 is connected to the S pole of the second magnet 22. As shown in FIG. 3A, the first yoke 32 is formed to be symmetric with respect to the axis Y.

  When the first magnet 21 and the second magnet 22 move relative to the Hall element 51 as the stroke portion 61 moves linearly, the magnetic flux density detected by the magnetic sensitive surface 511 is as shown in FIG. Change.

In the present embodiment, the use of the first yoke 32 increases the permeance of the magnetic circuit. For this reason, demagnetization of the first magnet 21 and the second magnet 22 can be suppressed, the magnetic flux density detected by the Hall element 51 can be increased, and the SN ratio can be improved.
Further, due to the shielding effect, the magnetic field on the opposite side of the first magnet 21 and the second magnet 22 with respect to the first yoke 32 and the disturbance due to the proximity of the magnetic material are strong. Therefore, the magnetic flux vector becomes more uniform, and the robustness is further enhanced.

(Third embodiment)
A stroke amount detection device according to a third embodiment of the present invention is shown in FIG. In addition, the same code | symbol is attached | subjected to the site | part substantially the same as 2nd Embodiment, and description is abbreviate | omitted.
As shown in FIG. 4A, in the stroke amount detection device 3 of the present embodiment, a V-shaped first convex portion 324 is formed on the third wall 323. The first convex portion 324 is formed at an intermediate portion of the third wall 323 and is formed to protrude toward the horizontal axis X in the Y direction.

  When the first magnet 21 and the second magnet 22 move relative to the Hall element 51 as the stroke portion 61 moves linearly, the magnetic flux density detected by the magnetic sensitive surface 511 is as shown in FIG. Change. A change in magnetic flux density detected by the stroke amount detection device 2 of the second embodiment is represented by a broken line G2, and a change of magnetic flux density detected by the stroke amount detection device 3 of the present embodiment is represented by a solid line G3.

  In the present embodiment, the first convex portion 324 is formed in the middle portion of the third wall 323. Thereby, the space | gap by the side of the horizontal axis X of the intermediate part of the 3rd wall 323 becomes narrow, and magnetic flux density can be raised. For this reason, the sensitivity of the Hall element 51 passing through the horizontal axis X side of the intermediate portion of the third wall 323 can be increased. Therefore, the linearity of the detected magnetic flux density of the Hall element 51 can be increased by increasing the gradient near the stroke 0 (see FIG. 4B).

(Fourth embodiment)
A stroke amount detection device according to a fourth embodiment of the present invention is shown in FIG. In addition, the same code | symbol is attached | subjected to the site | part substantially the same as 3rd Embodiment, and description is abbreviate | omitted.
As shown in FIG. 5, in the stroke amount detection device 4 of the present embodiment, an arc-shaped first convex portion 325 is formed on the third wall 323. The first convex portion 325 is formed to protrude toward the horizontal axis X in the Y direction. Thereby, 4th Embodiment has an effect similar to 3rd Embodiment.

(Fifth embodiment)
A stroke amount detection apparatus according to a fifth embodiment of the present invention is shown in FIG. In addition, the same code | symbol is attached | subjected to the site | part substantially the same as 3rd Embodiment, and description is abbreviate | omitted.
As shown in FIG. 6A, the stroke amount detection device 5 of the present embodiment is provided with a second yoke 35 on the side opposite to the first convex portion 324 with respect to the horizontal axis X. As shown in FIG. 7, the second yoke 35 is formed in a substantially L shape in a side view and includes a magnetic flux transmission wall 351 and a connection wall 352. The magnetic flux transmission wall 351 is provided at a position closer to the horizontal axis X than the first yoke 32. The connection wall 352 connects the magnetic flux transmission wall 351 and one end of the first convex portion 324 in the direction orthogonal to the horizontal axis X and the vertical axis Y. Here, the second yoke 35 corresponds to “second magnetic flux transmission means” in the claims.

  When the first magnet 21 and the second magnet 22 move relative to the Hall element 51 as the stroke portion 61 moves linearly, the magnetic flux density detected by the magnetic sensitive surface 511 is as shown in FIG. Change. A change in magnetic flux density detected by the stroke amount detection device 3 of the third embodiment is represented by a broken line G3, and a change of magnetic flux density detected by the stroke amount detection device 5 of the present embodiment is represented by a solid line G5.

  In the present embodiment, a second yoke 35 is provided on the side opposite to the first convex portion 324 with respect to the horizontal axis X. Thereby, compared with the stroke amount detection device 3 described in the third embodiment and the stroke amount detection device 4 described in the fourth embodiment, the gap near the zero point of the stroke amount on the horizontal axis X is narrowed. The magnetic flux density can be further increased. Therefore, compared with the stroke amount detection device 3 of the third embodiment, the linearity of the detected magnetic flux density of the Hall element 51 can be further increased by increasing the gradient near the stroke 0 (see FIG. 6B). ).

(Sixth embodiment)
A stroke amount detection device according to a sixth embodiment of the present invention is shown in FIG. In addition, the same code | symbol is attached | subjected to the site | part substantially the same as 2nd Embodiment, and description is abbreviate | omitted.
As shown in FIG. 8A, the stroke amount detection device 6 of the present embodiment is provided with a second yoke 36 on the side opposite to the first yoke 32 with respect to the horizontal axis X. The second yoke 36 is formed of a magnetic material such as a steel material, and has a U-shaped cross section including a fourth wall 364, a fifth wall 365, and a sixth wall 366 connecting the fourth wall 364 and the fifth wall 365. It is a frame shape. Here, the second yoke 36 corresponds to “second magnetic flux transmission means” in the claims.

  The end of the fourth wall 364 opposite to the sixth wall 366 is connected to the S pole of the first magnet 21. The end of the fifth wall 365 opposite to the sixth wall 366 is connected to the S pole of the second magnet 22. As shown in FIG. 8A, in the present embodiment, the first yoke 32 and the second yoke 36 are provided so as to be symmetric with respect to the horizontal axis X. The first yoke 32 and the second yoke 36 are formed so as to surround the first magnet 21 and the second magnet 22.

When the first magnet 21 and the second magnet 22 move relative to the Hall element 51 as the stroke portion 61 moves linearly, the magnetic flux density detected by the magnetic sensitive surface 511 is as shown in FIG. Change.
In the present embodiment, the first magnet 21 and the second magnet 22 are surrounded by the first yoke 32 and the second yoke 36. As a result, the shielding effect is enhanced in the horizontal axis X direction and the vertical axis Y direction, and the magnetic field outside the first yoke 32 and the second yoke 36 and disturbance due to the proximity of the magnetic material are enhanced. Therefore, compared with the stroke amount detection apparatus of the second embodiment to the fifth embodiment, the magnetic flux vector becomes more uniform and the robustness is further enhanced.

(Seventh embodiment)
A stroke amount detection apparatus according to a seventh embodiment of the present invention is shown in FIG. In addition, the same code | symbol is attached | subjected to the site | part substantially the same as 6th Embodiment, and description is abbreviate | omitted.
As shown in FIG. 9A, in the stroke amount detection device 7 of the present embodiment, an arc-shaped first convex portion 325 is formed on the third wall 323. The first convex portion 325 is formed to protrude to the horizontal axis line X side.

When the first magnet 21 and the second magnet 22 move relative to the Hall element 51 as the stroke portion 61 moves linearly, the magnetic flux density detected by the magnetic sensitive surface 511 is as shown in FIG. Change. A change in magnetic flux density detected by the stroke amount detection device 6 of the sixth embodiment is represented by a broken line G6, and a change of magnetic flux density detected by the stroke amount detection device 7 of the present embodiment is represented by a solid line G7.
In the present embodiment, the linearity of the detected magnetic flux density of the Hall element 51 can be further improved as compared with the stroke amount detection device 6 of the sixth embodiment.

(Eighth embodiment)
FIG. 10A shows a stroke amount detection device according to an eighth embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the site | part substantially the same as 7th Embodiment, and description is abbreviate | omitted.
As shown in FIG. 10A, in the stroke amount detection device 8 of the present embodiment, an arc-shaped second convex portion 367 is formed on the sixth wall 366. The 2nd convex part 367 protrudes in the horizontal axis line X side, and is formed. As shown in FIG. 10A, the first convex portion 325 and the second convex portion 367 are formed to be symmetric with respect to the horizontal axis X.

When the first magnet 21 and the second magnet 22 move relative to the Hall element 51 as the stroke portion 61 moves linearly, the magnetic flux density detected by the magnetosensitive surface 511 is as shown in FIG. To change. A change in magnetic flux density detected by the stroke amount detection device 6 of the sixth embodiment is represented by a broken line G6, and a change of magnetic flux density detected by the stroke amount detection device 8 of the present embodiment is represented by a solid line G8.
In the present embodiment, the linearity of the detected magnetic flux density of the Hall element 51 can be further improved as compared with the stroke amount detection device 7 described in the seventh embodiment.

(Ninth embodiment)
FIG. 11 shows a stroke amount detection device according to the ninth embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the site | part substantially the same as 2nd Embodiment, and description is abbreviate | omitted.
In the stroke amount detection device 9 of the present embodiment, the Hall IC chip 50 is fixed between the horizontal axis X and the third wall 323 of the first yoke 32. As a result, the Hall element 51 moves relative to the first magnet 21 and the second magnet 22 on a virtual straight line X1 parallel to the horizontal axis X between the horizontal axis X and the third wall 323.

(10th Embodiment)
A stroke amount detection device according to a tenth embodiment of the present invention is shown in FIG. In addition, the same code | symbol is attached | subjected to the site | part substantially the same as 2nd Embodiment, and description is abbreviate | omitted.
In the stroke amount detection device 10 of this embodiment, the Hall IC chip 50 is fixed to the opposite side of the third wall 323 of the first yoke 32 with respect to the horizontal axis X. Thereby, the Hall element 51 moves relative to the first magnet 21 and the second magnet 22 on the virtual straight line X2 on the opposite side of the third wall 323 of the first yoke 32 with respect to the horizontal axis X.
In the ninth embodiment and the tenth embodiment, the Hall element 51 is not fixed on the horizontal axis X. For this reason, it is possible to cope with different mounting variations of the first magnet 21, the second magnet 22, and the Hall element 51.

(Eleventh embodiment)
FIG. 13 shows a stroke amount detection apparatus according to an eleventh embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the site | part substantially the same as 2nd Embodiment, and description is abbreviate | omitted.
In the stroke amount detection device 11 of the present embodiment, a first protrusion 326 is formed on the first wall 321, and a second protrusion 327 is formed on the second wall 322. The first protrusion 326 is formed so as to protrude from the first magnet 21 to the opposite side of the third wall 323 with respect to the first wall 321. The second protruding portion 327 is formed to protrude from the second magnet 22 to the opposite side of the third wall 323 with respect to the second wall 322.

  In the present embodiment, a first protrusion 326 and a second protrusion 327 are formed. Accordingly, the amount of magnetic flux entering the first magnet 21 and the second magnet 22 through the first protrusion 326 and the second protrusion 327 increases. For this reason, the value of the minimum magnetic flux density in the 1st magnet 21 and the 2nd magnet 22 rises, and the permeance of a magnetic circuit improves. Therefore, compared with the stroke amount detection apparatus of 2nd Embodiment-5th Embodiment, the magnetic flux density which the Hall element 51 detects can be increased more, and SN ratio can be improved more.

(Twelfth embodiment)
A stroke amount detection device according to a twelfth embodiment of the present invention is shown in FIGS. In addition, the same code | symbol is attached | subjected to the site | part substantially the same as 2nd Embodiment, and description is abbreviate | omitted.
In the stroke amount detection device 12 of the present embodiment, the Hall element 51 is fixed at a point O1 between the first magnet 21 and the second magnet 22 in a stationary state, as shown in FIG. The magnetic surface 511 is provided so as to be orthogonal to the X direction. The point O1 is located on the left side of the middle point O on the horizontal axis X, and is separated from the middle point O by ΔL. That is, the first magnet 21 and the second magnet 22 are asymmetrically arranged with respect to a reference plane that is orthogonal to the horizontal axis X and includes the vertical axis Y.

  When the first magnet 21 and the second magnet 22 move relative to the Hall element 51 as the stroke portion 61 moves linearly, the magnetic flux density detected by the magnetic sensitive surface 511 is as shown in FIG. Change. Here, when the position of the Hall element 51 coincides with the point O1, the relative stroke amount is set to zero.

  A modification of this embodiment is shown in FIG. In the modification of the present embodiment, the Hall element 51 is fixed on the horizontal axis X between the first magnet 21 and the second magnet 22 as shown in FIG. It is provided so as to be orthogonal to the direction. The point O2 is located on the right side of the middle point O on the horizontal axis X, and is separated from the middle point O by ΔL.

  In the modification of this embodiment, when the Hall element 51 moves relative to the first magnet 21 and the second magnet 22 along with the linear movement of the stroke portion 61, the magnetic flux density detected by the magnetosensitive surface 511 is It changes as shown in 15 (B). Here, when the position of the Hall element 51 coincides with the point O2, the relative stroke amount is set to zero.

  In the present embodiment, the first magnet 21 and the second magnet 22 are arranged so as to be asymmetric with respect to the vertical axis Y. For this reason, in addition to the position where the relative stroke amount is 0, a position where the magnetic flux density with high detection accuracy is 0 can be set.

(13th Embodiment)
16 and 17 show a stroke amount detection device according to a thirteenth embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the site | part substantially the same as 2nd Embodiment, and description is abbreviate | omitted.
In the stroke amount detection device 13 of this embodiment, the first magnet 21 is formed larger than the second magnet 22 as shown in FIG. When the Hall element 51 moves relative to the first magnet 21 and the second magnet 22 along with the linear movement of the stroke portion 61, the magnetic flux density detected by the magnetic sensitive surface 511 is as shown in FIG. Change.

  A modification of this embodiment is shown in FIG. In the modification of the present embodiment, the second magnet 22 is formed larger than the first magnet 21 as shown in FIG. When the first magnet 21 and the second magnet 22 move relative to the Hall element 51 as the stroke portion 61 moves linearly, the magnetic flux density detected by the magnetic sensitive surface 511 is as shown in FIG. Change.

  In the present embodiment, since the first magnet 21 and the second magnet 22 are different in size, the position where the magnetic flux density is 0 is different from the middle point O. Thereby, in addition to the position where the relative stroke amount is 0, a position where the magnetic flux density with high detection accuracy is 0 can be set.

(Other embodiments)
In the said embodiment, a Hall element is fixed and a 1st magnet and a 2nd magnet move with a stroke part. On the other hand, in another embodiment, the first magnet and the second magnet may be fixed, and the Hall element may move with the stroke portion.
As mentioned above, this invention is not limited to the said embodiment at all, In the range which does not deviate from the meaning of invention, it can implement with a various form.

1 to 13: Stroke amount detection device 3: Linear actuator (detection target)
21 ... 1st magnet (1st magnetic field generation means)
22 ... 2nd magnet (2nd magnetic field generation means)
32 ... 1st yoke (1st magnetic flux transmission means)
35 ... 2nd yoke (2nd magnetic flux transmission means)
36 ... 2nd yoke (2nd magnetic flux transmission means)
51 ... Hall element (magnetic detection means)
324 ... 1st convex part 325 ... 1st convex part 367 ... 2nd convex part X ... Horizontal axis (virtual axis)
Y ... Vertical axis X1 ... Virtual straight line X2 ... Virtual straight line

Claims (10)

A stroke amount detection device that detects a stroke amount of a detection target that moves linearly,
A first magnetic field generating means and a second magnetic field generating means which are arranged to face each other in the stroke direction, are magnetized so that the opposing magnetic poles become magnetic poles of the same polarity, and move along with the linear movement of the detection target; ,
A magnetosensitive surface substantially orthogonal to the stroke direction is provided, and on a virtual axis passing through the first magnetic field generating means and the second magnetic field generating means along the stroke direction, or on a virtual straight line parallel to the virtual axis A magnetic detection means for detecting a change in the magnetic field by moving relative to the first magnetic field generation means and the second magnetic field generation means;
First magnetic flux transmission means for connecting magnetic poles opposite to the opposing magnetic poles of the first magnetic field generation means and the second magnetic field generation means,
The first magnetic flux transmission means has a first convex portion protruding toward the imaginary axis at an intermediate portion in the stroke direction . Further comprising second magnetic flux transmission means on the opposite side of the virtual axis from the intermediate portion of the first magnetic flux transmission means;
2. The stroke amount detection device according to claim 1 , wherein the second magnetic flux transmission unit is connected to one end of the intermediate portion of the first magnetic flux transmission unit in a direction orthogonal to the virtual axis. A second magnetic flux transmission means on the opposite side of the first magnetic flux transmission means with respect to the virtual axis;
2. The stroke amount detection device according to claim 1 , wherein the second magnetic flux transmission unit connects magnetic poles opposite to the opposing magnetic poles of the first magnetic field generation unit and the second magnetic field generation unit. The stroke amount detection device according to claim 3 , wherein the second magnetic flux transmission means has a second convex portion projecting toward the imaginary axis at an intermediate portion in the stroke direction. The stroke amount detection device according to any one of claims 2 to 4 , wherein the first magnetic flux transmission means and the second magnetic flux transmission means are arranged symmetrically with respect to the virtual axis. Wherein the first magnetic flux transmitting means second magnetic flux transmission means, claims 2 to characterized in that from said first magnetic field generating means and said second magnetic field generating means which is symmetrical with respect to equidistant reference plane stroke amount detecting apparatus according to any one of 5. The first magnetic field generating means and the second magnetic field generating means have the same magnetic characteristics and are arranged symmetrically with respect to a reference plane equidistant from the first magnetic field generating means and the second magnetic field generating means. The stroke amount detection device according to any one of claims 1 to 6 , wherein Stroke amount detecting apparatus according to any one of claims 1 to 6, characterized in that it has a size different from the first magnetic field generating means and the second magnetic field generating means. The stroke amount according to any one of claims 1 to 8 , wherein the magnetic detection means moves relative to the first magnetic field generation means and the second magnetic field generation means on the virtual axis. Detection device. 2. The magnetic detection unit moves relative to the first magnetic field generation unit and the second magnetic field generation unit on a virtual straight line that is parallel to the virtual axis and different from the virtual axis. stroke amount detecting apparatus according to any one of 1-8.

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