Linear drive system and head-up display device

Abstract

The present invention provides a linear drive device that suppresses rattling in the engagement portion of the driven object and reduces the cost of its components. [Solution] A linear drive device for driving an object to be driven comprises a motor having a lead screw shaft and a movable body that engages with the lead screw shaft and with the engaging portion of the object to be driven. The movable body comprises a nut member on which the lead screw shaft is positioned on the inner circumference side and a slide member 30 that moves linearly in the axial direction of the lead screw shaft together with the nut member. The slide member 30 is integrally formed with a nut holding portion 30b that holds the nut member, a support portion 30c that the engaging portion of the object to be driven contacts from the X1 direction side, and an elastic piece portion 30d that is elastically deformable in the axial direction of the lead screw shaft. The elastic piece portion 30d is positioned on the X1 direction side of the support portion 30c and contacts the engaging portion of the object to be driven from the X1 direction side, biasing the engaging portion toward the X2 direction side.

Description

Technical Field

[0001] The present invention relates to a linear drive device. The present invention also relates to a head-up display device.

Background Art

[0002] Conventionally, a drive device used in a head-up display device mounted on a vehicle is known (for example, see Patent Document 1). The drive device described in Patent Document 1 rotates the mirror holder by moving a protruding piece of the mirror holder that holds a concave mirror. This drive device includes a lead screw, a drive unit that rotates the lead screw, and a movable member that engages with the lead screw and moves in the axial direction of the lead screw. The movable member includes a nut unit, a main body portion that moves integrally with the nut unit in the axial direction, and a support portion that supports the protruding piece of the mirror holder. The support portion includes an elastic support portion that biases the protruding piece of the mirror holder toward one side in the axial direction, and a fixed support portion that supports the protruding piece biased by the elastic support portion.

[0003] In the drive device described in Patent Document 1, the elastic support portion includes an elastic member that abuts against the protruding piece and biases the protruding piece toward the fixed support portion, and an elastic member fixing portion to which the elastic member is fixed. The elastic member is a leaf spring and is composed of a fixing plate portion fixed to the elastic member fixing portion and an elastically deformable elastic deformation plate portion connected to the fixing plate portion. In the drive device described in Patent Document 1, since the protruding piece of the mirror holder is supported in a state of being pressed against the fixed support portion by the elastic support portion, even if the vehicle vibrates and the head-up display device vibrates, rattling of the protruding piece can be suppressed, and rattling of the mirror holder and the concave mirror can be suppressed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] As described above, the drive device described in Patent Document 1 makes it possible to suppress rattling of the protruding piece of the mirror holder. On the other hand, in this drive device, the elastic member for suppressing rattling of the protruding piece of the mirror holder is formed separately from the elastic member fixing part. Furthermore, the elastic member is a leaf spring composed of a fixing plate part and an elastic deformation plate part, and the shape of the elastic member is relatively complex. For this reason, the cost of the components constituting the drive device described in Patent Document 1 may be high.

[0006] Therefore, an object of the present invention is to provide a linear drive device that has a movable body that moves linearly in the axial direction of the lead screw shaft and engages with an engaging portion of the object to be driven, and that can suppress rattling of the engaging portion of the object to be driven, while also being able to reduce the cost of the components constituting the linear drive device. Another object of the present invention is to provide a head-up display device equipped with such a linear drive device. [Means for solving the problem]

[0007] To solve the above problems, one aspect of the present invention provides a linear drive device for driving an object to be driven, comprising: a motor having a lead screw shaft; and a movable body that engages with the lead screw shaft and moves linearly in the axial direction of the lead screw shaft when the lead screw shaft rotates, and which engages with an engagement portion of the object to be driven, wherein the movable body comprises a nut member on which the lead screw shaft is positioned on the inner circumference side, and a slide member that moves linearly in the axial direction of the lead screw shaft together with the nut member, wherein one side in the axial direction of the lead screw shaft is designated as the first direction side, and the other side in the axial direction of the lead screw shaft, opposite to the first direction side, is designated as the second direction side, wherein the slide member is integrally formed with a nut holding portion for holding the nut member, a support portion that the engagement portion contacts from the first direction side, and an elastic piece portion that is elastically deformable in the axial direction of the lead screw shaft, wherein the elastic piece portion is positioned on the first direction side of the support portion and contacts the engagement portion from the first direction side to bias the engagement portion toward the second direction side.

[0008] In this embodiment of the linear drive device, the slide member is formed with a support portion that contacts the engaging portion of the object to be driven from the first direction side, and an elastically deformable elastic piece that contacts the engaging portion from the first direction side and biases the engaging portion toward the second direction side. Therefore, in this embodiment, it is possible to suppress rattling of the engaging portion of the object to be driven by the biasing force of the elastic piece. Furthermore, in this embodiment, since the elastic piece is formed integrally with the nut holding portion and the support portion, it is possible to reduce the cost of the components constituting the linear drive device compared to the case in which the elastic piece is formed separately from the nut holding portion and the support portion. In other words, in this embodiment, it is possible to reduce the cost of the components constituting the linear drive device even though it is possible to suppress rattling of the engaging portion of the object to be driven.

[0009] The linear drive device of this embodiment can be used, for example, in a head-up display device equipped with a mirror holding member. In this head-up display device, for example, the first contact portion of the engaging portion, which is the part that contacts the support portion, and the second contact portion of the engaging portion, which is the part that contacts the elastic piece portion, are formed in a convex curved shape. In this head-up display device, it is possible to suppress rattling of the engaging portion of the object to be driven, while reducing the cost of the components constituting the linear drive device. [Effects of the Invention]

[0010] As described above, in one aspect of the present invention, in a linear drive device that includes a movable body which moves linearly in the axial direction of the lead screw shaft and engages with the engaging portion of the object to be driven, it is possible to suppress rattling of the engaging portion of the object to be driven, while also reducing the cost of the components constituting the linear drive device. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a perspective view of a linear drive device according to an embodiment of the present invention. [Figure 2] Figure 2 is a schematic diagram illustrating the configuration of a head-up display device that uses the linear drive mechanism shown in Figure 1. [Figure 3] Figure 3 is a side view of the linear drive device shown in Figure 1. [Figure 4] Figure 4 is a perspective view of the sliding member shown in Figure 1. [Figure 5] Figure 5 is a perspective view showing the sliding member shown in Figure 4 from a different direction. [Figure 6] Figure 6 is a cross-sectional view of the sliding member shown in Figure 4. [Figure 7] Figure 7 is a plan view illustrating the state in which the engaging portion is engaged with the sliding member shown in Figure 4. [Figure 8] Figure 8 is a perspective view illustrating the configuration of a movable body according to another embodiment of the present invention. [Figure 9]Figure 9 is a cross-sectional view of the slide member and leaf spring shown in Figure 8. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will be described below with reference to the drawings.

[0013] (Overall configuration of the linear drive system) Figure 1 is a perspective view of a linear drive device 2 according to an embodiment of the present invention. Figure 2 is a schematic diagram illustrating the configuration of a head-up display device 3 in which the linear drive device 2 shown in Figure 1 is used. Figure 3 is a side view of the linear drive device 2 shown in Figure 1.

[0014] The linear drive device 2 of this embodiment is used, for example, mounted in a head-up display device 3 (hereinafter referred to as "HUD device 3") installed in the dashboard (instrument panel) of an automobile. The HUD device 3 projects a virtual image onto the windshield 4 of the automobile, for example. The HUD device 3 comprises a display unit 5 that emits display light, a mirror unit 6 that reflects the display light emitted from the display unit 5 toward the windshield 4, and a housing 7 that houses the display unit 5 and the mirror unit 6.

[0015] The mirror unit 6 comprises a reflective mirror 8 that reflects the display light emitted from the display unit 5, a mirror holder 9 which serves as a mirror holding member to which the reflective mirror 8 is fixed, and a frame 10 which rotatably holds the mirror holder 9. The display unit 5 is, for example, a liquid crystal display and emits display light toward the reflective mirror 8 when the HUD device 3 is in use. The reflective mirror 8 is a concave mirror. The mirror holder 9 is rotatable relative to the frame 10 with an axis L parallel to the horizontal as its pivot point.

[0016] The linear drive device 2 of this embodiment is a device for driving the mirror holder 9. Specifically, the linear drive device 2 is a device for rotating the mirror holder 9 with respect to the frame 10. The linear drive device 2 is housed in the housing 7. The mirror holder 9 includes an engaging portion 11 that engages with a movable body 18, which will be described later, that forms part of the linear drive device 2. The engaging portion 11 is formed in a spherical shape. The mirror holder 9 of this embodiment is the object to be driven. That is, the HUD device 3 includes the linear drive device 2 and the mirror holder 9 that is the object to be driven.

[0017] In addition to the engaging portion 11, the mirror holder 9 includes two shaft portions 12 to which the engaging portion 11 is fixed, and two shaft fixing portions 13 to which the shaft portions 12 are fixed. The engaging portion 11, the shaft portions 12, and the shaft fixing portions 13 constitute the lower end portion of the mirror holder 9. The engaging portion 11, the shaft portions 12, and the shaft fixing portions 13 are disposed below the axis L in the vertical direction. The shaft portion 12 is formed, for example, in a columnar shape with the direction of the axis L as the axial direction. The shaft portion 12 protrudes from both sides of the engaging portion 11 in the direction of the axis L. The outer diameter of the shaft portion 12 is smaller than the outer diameter of the engaging portion 11. The outer end portion of the shaft portion 12 in the direction of the axis L is fixed to the shaft fixing portion 13 (see FIG. 7).

[0018] The linear drive device 2 includes a motor 17 and a movable body 18 that linearly moves by the power of the motor 17. The motor 17 is a stepping motor. The motor 17 includes a rotor having a rotary shaft 19 and a drive magnet, and a stator 20 having a drive coil and disposed on the outer peripheral side of the drive magnet. The output side portion of the rotary shaft 19 protrudes to the output side from the stator 20. The portion of the rotary shaft 19 that protrudes from the stator 20 is a feed screw shaft (lead screw) 19b having a feed screw formed on its outer peripheral surface. That is, the motor 17 includes the feed screw shaft 19b.

[0019] The movable body 18 engages with the lead screw shaft 19b and moves linearly in the axial direction of the lead screw shaft 19b as the lead screw shaft 19b rotates. The engaging portion 11 of the mirror holder 9 engages with the movable body 18. As the movable body 18 moves, the mirror holder 9 rotates relative to the frame 10 with axis L as the pivot point. In addition to the motor 17 and the movable body 18, the linear drive device 2 includes a position detection mechanism 21 for detecting the position of the movable body 18 in the axial direction of the lead screw shaft 19b, and two guide shafts 22 for guiding the movable body 18 in the axial direction of the lead screw shaft 19b.

[0020] In the following explanation, the X direction in Figure 1, which corresponds to the axial direction of the rotation axis 19 (i.e., the axial direction of the lead screw axis 19b), will be referred to as the front-rear direction. The side in the X1 direction in Figure 1, which corresponds to one side of the front-rear direction, will be referred to as the "front" side, and the side in the X2 direction in Figure 1, which corresponds to the other side of the front-rear direction, will be referred to as the "rear" side. Furthermore, for the sake of explanation, the Y direction in Figure 1, which is perpendicular to the front-rear direction, will be referred to as the left-right direction, and the Z direction in Figure 1, which is perpendicular to both the front-rear direction and the left-right direction, will be referred to as the up-down direction. Additionally, the side in the Z1 direction in Figure 1, which corresponds to one side of the up-down direction, will be referred to as the "up" side, and the side in the Z2 direction in Figure 1, which corresponds to the other side of the up-down direction, will be referred to as the "down" side.

[0021] In this configuration, the linear drive unit 2 is mounted on the HUD device 3 such that the axis L of the HUD device 3 is parallel to the left-right direction (Y direction). Furthermore, the linear drive unit 2 is mounted on the HUD device 3 such that its upper side (Z1 direction side) and its vertically upper side (the side on which the windshield 4 is positioned relative to the HUD device 3) coincide (i.e., its lower side (Z2 direction side) and its vertically lower side coincide).

[0022] In this embodiment, the front side (X1 direction side) is the first direction side, which is one side in the axial direction of the lead screw shaft 19b, and the rear side (X2 direction side) is the second direction side, which is the other side in the axial direction of the lead screw shaft 19b. Furthermore, the vertical direction (Z direction) in this embodiment is the first orthogonal direction, which is a predetermined direction perpendicular to the axial direction of the lead screw shaft 19b. Also, the upper side (Z1 direction side) is the third direction side, which is one side of the first orthogonal direction, and the lower side (Z2 direction side) is the fourth direction side, which is the opposite side of the third direction. The left-right direction (Y direction) is the second orthogonal direction, which is perpendicular to the axial direction of the lead screw shaft 19b and the first orthogonal direction.

[0023] In addition to the rotor and stator 20, the motor 17 includes a frame 24 to which the stator 20 is fixed, an output-side bearing 25 that supports the front portion of the rotating shaft 19 (i.e., the output-side portion of the lead screw shaft 19b), a non-output-side bearing that supports the rear portion of the rotating shaft 19, and a leaf spring 26 that contacts the rear end of the rotating shaft 19 and biases the rotating shaft 19 forward. The frame 24 is fixed, for example, to the frame 10 of the HUD device 3. The output-side bearing 25 supports the rotating shaft 19 in the axial (front-rear direction) and radial directions of the rotating shaft 19. The non-output-side bearing supports the rotating shaft 19 in the radial direction of the rotating shaft 19. The leaf spring 26 is fixed to the rear surface of the stator 20.

[0024] The frame 24 comprises a flat bottom portion 24b that forms the lower part of the frame 24, a flat side portion 24c that rises upward from the front portion of the bottom portion 24b, a flat side portion 24d that rises upward from the rear portion of the bottom portion 24b, and a flat fixing portion 24e to which the position detection mechanism 21 is fixed. The thickness direction of the bottom portion 24b and the thickness direction of the fixing portion 24e coincide with the vertical direction. The thickness directions of the side portions 24c and 24d coincide with the left-right direction.

[0025] The side portion 24c rises perpendicularly from the front end of the bottom portion 24b. The side portion 24d rises perpendicularly from the rear end of the bottom portion 24b. The fixing portion 24e extends forward from the upper end of the side portion 24d. The side portion 24c holds the output side bearing 25. The front end surface of the stator 20 is fixed to the side portion 24d. A through hole is formed in the side portion 24d in which a part of the rotating shaft 19 is positioned. The front end of the guide shaft 22 is fixed to the side portion 24c. The rear end of the guide shaft 22 is fixed to the side portion 24d.

[0026] The movable body 18 is positioned between the side portions 24c and 24d in the front-rear direction. The movable body 18 is also positioned above the bottom portion 24b. The specific configuration of the movable body 18 will be described later. The position detection mechanism 21 is a contact-type switch. The position detection mechanism 21 is attached to the upper surface of the fixed portion 24e. The position detection mechanism 21 is positioned behind the support portion 30c, which is part of the movable body 18 and will be described later, and detects the position of the movable body 18 from behind the movable body 18. The position detection mechanism 21 also detects the origin position of the movable body 18 in the front-rear direction.

[0027] (Configuration of the movable body) Figure 4 is a perspective view of the slider 30 shown in Figure 1. Figure 5 is a perspective view of the slider 30 shown in Figure 4 from a different direction. Figure 6 is a cross-sectional view of the slider 30 shown in Figure 4. Figure 7 is a plan view illustrating the state in which the engaging portion 11 is engaged with the slider 30 shown in Figure 4.

[0028] The movable body 18 comprises nut members 28 and 29 with the feed screw shaft 19b positioned on the inner circumference, a slider 30 as a sliding member that moves linearly in the front-rear direction together with the nut members 28 and 29, and a compression coil spring 31 for biasing the nut members 28 and 29. The movable body 18 in this embodiment comprises two nut members 28 and 29. Furthermore, the movable body 18 in this embodiment is composed of the nut members 28 and 29, the slider 30, and the compression coil spring 31.

[0029] The nut members 28 and 29 are resin molded products manufactured by resin molding. The nut members 28 and 29 are formed in a flanged cylindrical shape with the front-to-back direction as the axial direction. The inner circumference of the nut members 28 and 29 has a screw hole that engages with the feed screw shaft 19b. The nut members 28 and 29 are arranged with a gap between them in the front-to-back direction. The nut member 28 is positioned in front of the nut member 29. The front end of the nut member 28 has a flange portion 28b that extends radially outward from the nut member 28. The rear end of the nut member 29 has a flange portion 29b that extends radially outward from the nut member 29.

[0030] The slider 30 is a resin molded product manufactured by resin molding. The slider 30 has a nut holding portion 30b for holding nut members 28 and 29, a support portion 30c that the engaging portion 11 of the mirror holder 9 contacts from the front, and a plate-shaped elastic piece portion 30d that is elastically deformable in the front-rear direction. The elastic piece portion 30d is positioned in front of the support portion 30c. The elastic piece portion 30d contacts the engaging portion 11 from the front and biases the engaging portion 11 toward the rear. That is, the elastic piece portion 30d contacts the engaging portion 11 from the front and biases the engaging portion 11 toward the support portion 30c. The slider 30 also has two wall portions 30e positioned on both sides of the elastic piece portion 30d in the left-right direction, and a connecting portion 30f connecting the two wall portions 30e.

[0031] The slider 30 in this embodiment is composed of a nut holding portion 30b, a support portion 30c, an elastic piece portion 30d, a wall portion 30e, and a connecting portion 30f. The nut holding portion 30b, the support portion 30c, the elastic piece portion 30d, the wall portion 30e, and the connecting portion 30f are integrally formed. In other words, the slider 30 has the nut holding portion 30b, the support portion 30c, the elastic piece portion 30d, the wall portion 30e, and the connecting portion 30f integrally formed.

[0032] The nut holding portion 30b constitutes the lower end of the slider 30. The nut holding portion 30b has a guide hole 30g in which a part of the guide shaft 22 is positioned. The nut holding portion 30b also has a nut placement recess 30h in which nut members 28 and 29 are positioned. The nut placement recess 30h has a wall portion 30j that contacts the rear surface of the flange portion 28b of the nut member 28.

[0033] The cylindrical portions of the nut members 28 and 29 are positioned on the inner circumference side of the compression coil spring 31. The front end of the compression coil spring 31 is in contact with the rear surface of the wall portion 30j. The rear end of the compression coil spring 31 is in contact with the front surface of the flange portion 29b of the nut member 29. The compression coil spring 31 biases the nut member 29 toward the rear relative to the slider 30. Furthermore, due to the biasing force of the compression coil spring 31, the front surface of the wall portion 30j is in contact with the rear surface of the flange portion 28b of the nut member 28 with a predetermined contact pressure.

[0034] The support portion 30c rises upward from the nut holding portion 30b and is connected to the nut holding portion 30b. That is, the lower end of the support portion 30c is connected to the upper end of the nut holding portion 30b. The support portion 30c rises upward from the rear portion of the nut holding portion 30b. The support portion 30c is formed in the shape of a rectangular flat plate with the front-to-back direction as the thickness direction. The direction of the longer side of the rectangular flat plate-shaped support portion 30c coincides with the up-and-down direction.

[0035] The thickness of the support portion 30c is relatively thick. Specifically, the thickness of the support portion 30c is set so that it hardly undergoes elastic deformation even when the support portion 30c is pressed from the front by the engaging portion 11. The front and rear surfaces of the support portion 30c are planes perpendicular to the front-rear direction. The front surface of the support portion 30c is the contact surface that the engaging portion 11 contacts. The rear surface of the support portion 30c is the contact surface that the contact portion of the position detection mechanism 21 can contact.

[0036] The elastic piece 30d rises upward from the nut holding portion 30b and is connected to the nut holding portion 30b. That is, the lower end of the elastic piece 30d is connected to the upper end of the nut holding portion 30b. The elastic piece 30d rises upward from the front portion of the nut holding portion 30b. Also, the elastic piece 30d rises upward from the left-right central portion of the nut holding portion 30b. The elastic piece 30d is formed in the shape of a rectangular flat plate with the front-to-back direction as the thickness direction. The direction of the long side of the rectangular flat plate-shaped elastic piece 30d coincides with the up-and-down direction. The thickness of the elastic piece 30d is thinner than the thickness of the support portion 30c.

[0037] The width of the elastic piece 30d in the left-right direction is narrower than the width of the support portion 30c in the left-right direction. When no external force is applied to the elastic piece 30d, the front and rear surfaces of the elastic piece 30d are planes perpendicular to the front-rear direction. As described above, the elastic piece 30d is positioned in front of the support portion 30c. The support portion 30c and the elastic piece 30d are positioned opposite each other with a predetermined distance between them in the front-rear direction.

[0038] The wall portion 30e rises upward from the nut holding portion 30b and is connected to the nut holding portion 30b. That is, the lower end of the wall portion 30e is connected to the upper end of the nut holding portion 30b. The wall portion 30e rises upward from the front part of the nut holding portion 30b. The wall portion 30e is formed in a rectangular prism shape. The sides of the wall portion 30e are planes perpendicular to the front-to-back or left-to-right direction. The width of the wall portion 30e in the front-to-back direction is wider than the thickness (thickness in the front-to-back direction) of the elastic piece portion 30d.

[0039] The front surface of the wall section 30e is positioned in the same location in the front-rear direction as the front surface of the elastic piece section 30d when no external force is applied to the elastic piece section 30d. The rear surface of the wall section 30e is positioned further back than the rear surface of the elastic piece section 30d when no external force is applied to the elastic piece section 30d. The right surface of the wall section 30e located on the right side is positioned in the same location in the left-right direction as the right end surface of the support section 30c, and the left surface of the wall section 30e located on the left side is positioned in the same location in the left-right direction as the left end surface of the support section 30c. The height of the wall section 30e is greater than the height of the elastic piece section 30d. Also, the height of the wall section 30e is less than the height of the support section 30c. The connecting section 30f connects the upper ends of the two wall sections 30e.

[0040] As shown in Figure 6, the base end 30r of the elastic piece 30d (i.e., the lower end of the elastic piece 30d), which is the connection point between the elastic piece 30d and the nut holding portion 30b, is positioned below the base end 30t of the support portion (i.e., the lower end of the support portion 30c), which is the connection point between the support portion 30c and the nut holding portion 30b. The base end 30v of the wall portion 30e (i.e., the lower end of the wall portion 30e), which is the connection point between the wall portion 30e and the nut holding portion 30b, and the base end 30r of the elastic piece are positioned at the same location in the vertical direction. The support portion 30c and the wall portion 30e are connected by a concave curved surface that curves downwards.

[0041] As described above, the linear drive unit 2 is mounted on the HUD device 3 such that the direction of the axis L of the HUD device 3 is parallel to the left-right direction (Y direction), and the upper side (Z1 direction side) coincides with the vertical upper side. The engaging portion 11 is positioned from above between the support portion 30c and the elastic piece portion 30d. When the engaging portion 11 is positioned between the support portion 30c and the elastic piece portion 30d, the upper end of the elastic piece portion 30d contacts the engaging portion 11 from the front and bends toward the front, biasing the engaging portion 11 toward the rear.

[0042] Furthermore, as described above, since the mirror holder 9 is rotatable relative to the frame 10 with axis L as the pivot point, the contact points of the engaging portion 11 with the support portion 30c and the contact points of the engaging portion 11 with the elastic piece portion 30d change slightly as the mirror holder 9 rotates with axis L as the pivot point. Specifically, a predetermined portion on the rear side of the engaging portion 11 contacts the support portion 30c, and a predetermined portion on the front side of the engaging portion 11 contacts the elastic piece portion 30d.

[0043] Furthermore, the engaging portion 11 is formed in a spherical shape. Therefore, the first contact portion 11b (see Figure 7A), which is the part of the engaging portion 11 that contacts the support portion 30c, and the second contact portion 11c (see Figure 7A), which is the part of the engaging portion 11 that contacts the elastic piece portion 30d, are formed in a convex curved shape. In other words, the shape of the first contact portion 11b and the shape of the second contact portion 11c when viewed from the left and right directions are convex curves. Specifically, the shape of the first contact portion 11b and the shape of the second contact portion 11c when viewed from the left and right directions are arc-shaped.

[0044] When the engaging portion 11 is positioned between the support portion 30c and the elastic piece portion 30d, the wall portion 30e is slightly bent forward. When the engaging portion 11 is positioned between the support portion 30c and the elastic piece portion 30d, the engaging portion 11 is positioned between the two wall portions 30e in the left-right direction (see Figure 7A). Also, as shown in Figure 7A, when the engaging portion 11 is positioned between the support portion 30c and the elastic piece portion 30d, the shaft portion 12 is positioned between the support portion 30c and the wall portion 30e, and the shaft fixing portion 13 is positioned outside the slider 30 in the left-right direction.

[0045] In this embodiment, when an excessive load is applied to the lower end of the mirror holder 9 from the front, the shaft portion 12 contacts the wall portion 30e before the elastic piece portion 30d breaks, so that the elastic piece portion 30d does not deform excessively forward and break when the engaging portion 11 contacts it from the rear (see Figure 7B). In other words, when an excessive load is applied to the lower end of the mirror holder 9 from the front, the shaft portion 12 contacts the wall portion 30e before the base portion (lower end) of the elastic piece portion 30d breaks.

[0046] (Main effects of this form) As described above, in this embodiment, the slider 30 is formed with a support portion 30c that the engaging portion 11 contacts from the front, and an elastically deformable elastic piece portion 30d that contacts the engaging portion 11 from the front and biases the engaging portion 11 toward the rear. Therefore, in this embodiment, even if the vehicle on which the HUD device 3 is installed vibrates and the HUD device 3 vibrates, the biasing force of the elastic piece portion 30d makes it possible to suppress rattling of the engaging portion 11.

[0047] Furthermore, in this embodiment, since the elastic piece 30d is formed integrally with the nut holding portion 30b and the support portion 30c, the number of parts in the linear drive device 2 can be reduced compared to the case where the elastic piece 30d is formed separately from the nut holding portion 30b and the support portion 30c, thereby reducing the cost of the parts that constitute the linear drive device 2. In other words, in this embodiment, even if it is possible to suppress rattling of the engaging portion 11, it is possible to reduce the cost of the parts that constitute the linear drive device 2.

[0048] In this embodiment, the engaging portion 11 is positioned from above between the support portion 30c and the elastic piece portion 30d. Also, in this embodiment, the elastic piece portion 30d rises upward from the nut holding portion 30b. Therefore, in this embodiment, it is possible to increase the length of the elastic piece portion 30d while suppressing the height of the slider 30. Consequently, in this embodiment, it is possible to elastically deform the elastic piece portion 30d while suppressing the height of the slider 30. In particular, in this embodiment, since the base end 30r of the elastic piece portion is positioned below the base end 30t of the support portion, it is possible to further increase the length of the elastic piece portion 30d while suppressing the height of the slider 30. Consequently, in this embodiment, it is possible to elastically deform the elastic piece portion 30d more easily while suppressing the height of the slider 30.

[0049] In this embodiment, the slider 30 has wall portions 30e formed on both sides of the elastic piece portion 30d in the left-right direction. Furthermore, in this embodiment, when an excessive load is applied to the lower end of the mirror holder 9 towards the front, the shaft portion 12 contacts the wall portion 30e before the elastic piece portion 30d is damaged, so that the elastic piece portion 30d, which the engaging portion 11 contacts from the rear, does not deform excessively towards the front and break. Therefore, in this embodiment, it is possible to prevent damage to the elastic piece portion 30d caused by excessive deformation towards the front.

[0050] In this embodiment, the first contact portion 11b of the engaging portion 11 that contacts the support portion 30c, and the second contact portion 11c of the engaging portion 11 that contacts the elastic piece portion 30d are formed in a convex curved shape. Therefore, in this embodiment, even when the movable body 18 moves in the front-rear direction and the mirror holder 9 rotates relative to the frame 10 with the axis L as the pivot point, it is possible to maintain smooth contact between the engaging portion 11 and the support portion 30c, and also to maintain smooth contact between the engaging portion 11 and the elastic piece portion 30d.

[0051] (Example of modification of movable parts) Figure 8 is a perspective view illustrating the configuration of a movable body 18 according to another embodiment of the present invention. Figure 9 is a cross-sectional view of the slider 30 and leaf spring 35 shown in Figure 8.

[0052] In the above-described embodiment, the movable body 18 may include a flat leaf spring 35 positioned in front of the elastic piece 30d. The leaf spring 35 is formed in the shape of a long, narrow rectangle in the left-right direction. The leaf spring 35 is positioned such that its thickness direction coincides with its front-rear direction. The leaf spring 35 is held by the slider 30. Specifically, the leaf spring 35 is held by the wall portion 30e. That is, the right end of the leaf spring 35 is held by the wall portion 30e positioned on the right side, and the left end of the leaf spring 35 is held by the wall portion 30e positioned on the left side. The wall portion 30e has a positioning hole 30k formed therein where the end of the leaf spring 35 is positioned. The positioning hole 30k penetrates the wall portion 30e in the left-right direction.

[0053] The leaf spring 35 is positioned in front of the upper portion of the elastic piece 30d. Specifically, the leaf spring 35 is positioned in front of the upper end of the elastic piece 30d. The rear surface of the leaf spring 35 is in contact with the front surface of the elastic piece 30d. A protrusion 30p is formed on the front surface of the elastic piece 30d for positioning the leaf spring 35 relative to the elastic piece 30d in a direction perpendicular to the front-rear direction. The protrusion 30p projects forward from the front surface of the elastic piece 30d. The leaf spring 35 has an engagement hole 35b into which the protrusion 30p engages. The engagement hole 35b is a through hole that penetrates the leaf spring 35 in the front-rear direction.

[0054] In this modified example, in addition to the biasing force of the elastic piece 30d, the biasing force of the leaf spring 35 can be applied to the engagement portion 11. Therefore, even if a large external force acts on the mirror holder 9 and a large external force acts on the engagement portion 11, it becomes possible to suppress rattling of the engagement portion 11. In particular, in this modified example, since the leaf spring 35 is positioned in front of the upper part of the elastic piece 30d that rises upward from the nut holding portion 30b, it becomes possible to suppress rattling of the engagement portion 11 even if a large external force acts on the engagement portion 11.

[0055] Furthermore, in this modified example, the leaf spring 35 is formed in the shape of a rectangular flat plate, and the shape of the leaf spring 35 is simple. Therefore, it is possible to reduce the component cost of the leaf spring 35. Thus, in this modified example, even if the linear drive device 2 is equipped with a leaf spring, it is possible to reduce the cost of the components that make up the linear drive device 2. In this modified example, for example, the leaf spring 35 may be positioned in front of the middle portion in the vertical direction of the elastic piece 30d. Also, in this modified example, a small gap may be formed between the front surface of the elastic piece 30d and the rear surface of the leaf spring 35 when no external force is acting on the elastic piece 30d.

[0056] (Other embodiments) The above-described embodiments are examples of preferred embodiments of the present invention, but are not limited thereto, and various modifications can be made without altering the essence of the invention.

[0057] In the above-described embodiment, the slider 30 does not necessarily have a connecting portion 30f. That is, the upper ends of the two wall portions 30e do not necessarily have to be connected. Also, in the above-described embodiment, the wall portion 30e may be arranged only on one side of the elastic piece portion 30d in the left-right direction. Furthermore, in the above-described embodiment, the slider 30 does not necessarily have a wall portion 30e.

[0058] In the above-described embodiment, the base end 30r of the elastic piece may be positioned at the same location as the base end 30t of the support portion in the vertical direction, or it may be positioned above the base end 30t of the support portion. Furthermore, in the above-described embodiment, the slider 30 may have multiple elastic pieces 30d that rise upward from the nut holding portion 30b. In this case, the elastic pieces 30d may be formed, for example, in a columnar (rod) shape that is elastically deformable in the front-rear direction.

[0059] Furthermore, in the above-described embodiment, instead of the elastic piece portion 30d, for example, one or more elastic pieces extending downward from the connecting portion 30f may be formed on the slider 30. Alternatively, in addition to the elastic piece portion 30d, an elastic piece extending downward from the connecting portion 30f may be formed on the slider 30. In this case, the length of the elastic piece portion 30d is shorter than in the above-described embodiment. Also, instead of the elastic piece portion 30d, or in addition to the elastic piece portion 30d, for example, one or more elastic pieces extending inward in the left-right direction from one or two wall portions 30e may be formed on the slider 30. Even in these cases, the elastic piece portion is elastically deformable in the front-rear direction.

[0060] In the above-described configuration, the position detection mechanism 21 may be positioned in front of the movable body 18. In this case, for example, the elastic piece 30d may be positioned behind the support portion 30c. When the elastic piece 30d is positioned behind the support portion 30c, the rear side (X2 direction side) becomes the first direction side, which is one side in the axial direction of the lead screw shaft 19b, and the front side (X1 direction side) becomes the second direction side, which is the other side in the axial direction of the lead screw shaft 19b.

[0061] In the above-described configuration, a portion of the rotating shaft 19 is the lead screw shaft 19b, but the lead screw shaft 19b may be formed separately from the rotating shaft 19 and fixed to the rotating shaft 19. Also, in the above-described configuration, the motor 17 may be a motor other than a stepping motor. Furthermore, in the above-described configuration, the linear drive device 2 may be mounted and used on a device other than the HUD device 3. In other words, the object driven by the linear drive device 2 may be something other than the mirror holder 9.

[0062] In the above-described embodiment, only the first contact portion 11b and the second contact portion 11c of the engaging portion 11 may be formed in a spherical shape. That is, the entire engaging portion 11 does not have to be formed in a spherical shape. Also, in the above-described embodiment, the engaging portion 11 may be formed in a cylindrical shape with the axis L in the direction of the axis, or it may be formed in a disc shape with the axis L in the direction of the thickness. Even in this case, the first contact portion 11b and the second contact portion 11c are formed in a curved shape, and the shape of the first contact portion 11b and the shape of the second contact portion 11c when viewed from the left and right directions are convex curves.

[0063] (Configuration of this technology) Furthermore, this technology can be configured as follows: (1) In a linear drive device for driving an object to be driven, The system comprises a motor having a lead screw shaft, and a movable body that engages with the lead screw shaft and moves linearly in the axial direction of the lead screw shaft when the lead screw shaft rotates, and which engages with the engagement portion of the object to be driven. The movable body comprises a nut member on which the feed screw shaft is positioned on the inner circumference, and a slide member that moves linearly in the axial direction of the feed screw shaft together with the nut member. If one side of the feed screw shaft in the axial direction is designated as the first direction side, and the other side of the feed screw shaft in the axial direction, which is opposite to the first direction side, is designated as the second direction side, The slide member is integrally formed with a nut holding portion for holding the nut member, a support portion that the engaging portion contacts from the first direction side, and an elastic piece portion that is elastically deformable in the axial direction of the feed screw shaft. The linear drive device is characterized in that the elastic piece is positioned on the first direction side of the support portion and contacts the engaging portion from the first direction side to bias the engaging portion toward the second direction side. (2) If a predetermined direction perpendicular to the axial direction of the feed screw shaft is defined as the first orthogonal direction, and one side of the first orthogonal direction is defined as the third direction side, The support portion is connected to the nut holding portion and rises from the nut holding portion toward the third direction. The linear drive device according to (1), characterized in that the engaging portion is arranged between the support portion and the elastic piece portion from the third direction side. (3) The linear drive device according to (2), characterized in that the elastic piece is connected to the nut holding portion and rises from the nut holding portion toward the third direction. (4) If the side opposite to the third direction is designated as the fourth direction, The linear drive device according to (3), characterized in that the base end of the elastic piece, which is the connection portion between the elastic piece and the nut holding portion, is positioned on the fourth direction side than the base end of the support portion, which is the connection portion between the support portion and the nut holding portion. (5) If the direction perpendicular to the axial direction of the feed screw shaft and the first orthogonal direction is defined as the second orthogonal direction, The linear drive device according to any one of (2) to (4), characterized in that the slide member has a wall portion formed thereon that connects to the nut holding portion and rises from the nut holding portion toward the third direction, and is arranged on both sides or one side of the elastic piece portion in the second orthogonal direction. (6) The linear drive device according to any one of (1) to (5), characterized in that the movable body comprises a flat plate spring that is held by the slide member and positioned on the first direction side of the elastic piece. (7) The movable body comprises a flat plate-shaped leaf spring positioned on the first direction side of the elastic piece, If the direction perpendicular to the axial direction of the feed screw shaft and the first orthogonal direction is defined as the second orthogonal direction, The slide member has wall portions that connect to the nut holding portion, rise from the nut holding portion toward the third direction, and are arranged on both sides of the elastic piece portion in the second orthogonal direction. The linear drive device according to (3), characterized in that the leaf spring is held by the wall and is positioned on the first direction side of the third direction side portion of the elastic piece. (8) The linear drive device according to any one of (1) to (7), characterized in that the object to be driven is used in a head-up display device comprising a reflective mirror and a display unit that emits display light toward the reflective mirror, and the reflective mirror is fixed to a mirror holding member that is rotatably held on the frame of the head-up display device. (9)(8) comprises the linear drive device described above and the mirror holding member, A head-up display device characterized in that the first contact portion of the engaging portion, which is the part that contacts the support portion, and the second contact portion of the engaging portion, which is the part that contacts the elastic piece portion, are formed in a convex curved shape.

[0064] In this technology, for example, if a predetermined direction perpendicular to the axial direction of the lead screw shaft is defined as the first orthogonal direction, and one side of the first orthogonal direction is defined as the third direction, then the support portion is connected to the nut holding portion and rises from the nut holding portion toward the third direction, and the engaging portion is positioned between the support portion and the elastic piece portion from the third direction.

[0065] In this technology, it is preferable that the elastic piece is connected to the nut holding portion and rises from the nut holding portion toward the third direction. With this configuration, it is possible to increase the length of the elastic piece while suppressing the length of the slide member in the first orthogonal direction. Therefore, it becomes easier to elastically deform the elastic piece while suppressing the length of the slide member in the first orthogonal direction.

[0066] In this technology, if the side opposite the third direction is considered the fourth direction, it is preferable that the base end of the elastic piece, which is the connection point between the elastic piece and the nut holding portion, is positioned on the fourth direction side than the base end of the support portion, which is the connection point between the support portion and the nut holding portion. With this configuration, it becomes possible to increase the length of the elastic piece while suppressing the length of the slide member in the first orthogonal direction. Therefore, it becomes easier to elastically deform the elastic piece while suppressing the length of the slide member in the first orthogonal direction.

[0067] In this technology, for example, if the second orthogonal direction is the direction perpendicular to the axial direction of the lead screw shaft and the first orthogonal direction, the slide member has a wall formed thereon that connects to the nut holding portion and rises from the nut holding portion toward the third direction, and is positioned on both sides or one side of the elastic piece portion in the second orthogonal direction. In this case, it becomes possible to bring a part of the object to be driven into contact with the wall before excessive deformation occurs in the elastic piece portion toward the first direction. Therefore, it becomes possible to prevent damage to the elastic piece portion caused by excessive deformation toward the first direction.

[0068] In this technology, it is preferable that the movable body includes a flat plate-shaped leaf spring that is held by a sliding member and positioned on the first direction side of the elastic piece. With this configuration, it becomes possible to apply the biasing force of the leaf spring to the engagement part of the driven object in addition to the biasing force of the elastic piece. Therefore, even if a large external force is applied to the engagement part of the driven object, it becomes possible to suppress rattling of the engagement part of the driven object. Furthermore, the shape of the flat plate-shaped leaf spring is simple, and it is possible to reduce the cost of the leaf spring component. Therefore, even if the linear drive device is equipped with a leaf spring, it is possible to reduce the cost of the components that make up the linear drive device.

[0069] In this technology, the movable body is provided with a flat plate-shaped leaf spring positioned on the first direction side of the elastic piece, and if the direction perpendicular to the axial direction of the feed screw shaft and the first orthogonal direction is defined as the second orthogonal direction, the slide member is formed with wall portions that connect to the nut holding portion and rise from the nut holding portion toward the third direction, and are positioned on both sides of the elastic piece in the second orthogonal direction, and the leaf spring is held by the wall portions and is positioned on the first direction side of the portion of the elastic piece toward the third direction.

[0070] With this configuration, it becomes possible to bring a portion of the driven object into contact with the wall before excessive deformation occurs in the elastic piece in the first direction. Therefore, it becomes possible to prevent damage to the elastic piece caused by excessive deformation in the first direction. Furthermore, with this configuration, it becomes possible to effectively apply the biasing force of the leaf spring to the engagement portion of the driven object in addition to the biasing force of the elastic piece. Therefore, even if a large external force is applied to the engagement portion of the driven object, it becomes possible to suppress rattling of the engagement portion of the driven object. Since the leaf spring is formed in a flat plate shape, as described above, even if the linear drive device is equipped with a leaf spring, it is possible to reduce the cost of the components constituting the linear drive device.

[0071] In this technology, for example, the object to be driven is a mirror holding member used in a head-up display device that includes a reflective mirror and a display unit that emits display light toward the reflective mirror, and the reflective mirror is fixed to it while the mirror is rotatably held by the frame of the head-up display device. [Explanation of symbols]

[0072] 2 Linear drive unit 3. HUD (Head-Up Display) 5 Display 8 Reflective mirrors 9. Mirror holder (mirror holding member, object to be driven) 10 frames 11 Engagement part 11b 1st contact part 11c 2nd contact part 17 Motor 18 Movable body 19b Feed screw shaft 28, 29 Nut components 30 Slider (sliding component) 30b Nut retaining part 30c support part 30d Elastic piece 30e wall 30r elastic piece base end 30t Support base end 35 Leaf springs X Axial direction of the lead screw axis X1 1st direction side X2 2nd direction side Y Second orthogonal direction Z First orthogonal direction Z1 3rd direction side Z2 4th direction side

Claims

1. In a linear drive device for driving an object to be driven, The system comprises a motor having a lead screw shaft, and a movable body that engages with the lead screw shaft and moves linearly in the axial direction of the lead screw shaft when the lead screw shaft rotates, and which engages with the engagement portion of the object to be driven. The movable body comprises a nut member on which the feed screw shaft is positioned on the inner circumference, and a slide member that moves linearly in the axial direction of the feed screw shaft together with the nut member. If one side of the feed screw shaft in the axial direction is designated as the first direction, and the other side of the feed screw shaft in the axial direction, which is opposite to the first direction, is designated as the second direction, The slide member is integrally formed with a nut holding portion for holding the nut member, a support portion that the engaging portion contacts from the first direction side, and an elastic piece portion that is elastically deformable in the axial direction of the feed screw shaft. The linear drive device is characterized in that the elastic piece is positioned on the first direction side of the support portion and contacts the engaging portion from the first direction side to bias the engaging portion toward the second direction side.

2. If a predetermined direction perpendicular to the axial direction of the feed screw shaft is defined as the first orthogonal direction, and one side of the first orthogonal direction is defined as the third direction, The support portion is connected to the nut holding portion and rises from the nut holding portion toward the third direction. The linear drive device according to claim 1, characterized in that the engaging portion is arranged between the support portion and the elastic piece portion from the third direction side.

3. The linear drive device according to claim 2, characterized in that the elastic piece is connected to the nut holding portion and rises from the nut holding portion toward the third direction.

4. If we consider the side opposite to the aforementioned third direction as the fourth direction, The linear drive device according to claim 3, characterized in that the base end of the elastic piece, which is the connection portion between the elastic piece and the nut holding portion, is positioned on the fourth direction side than the base end of the support portion, which is the connection portion between the support portion and the nut holding portion.

5. If the direction perpendicular to the axial direction of the feed screw shaft and the first orthogonal direction is defined as the second orthogonal direction, The linear drive device according to claim 2, characterized in that the slide member has a wall portion formed thereon that connects to the nut holding portion and rises from the nut holding portion toward the third direction, and is arranged on both sides or one side of the elastic piece portion in the second orthogonal direction.

6. The linear drive device according to any one of claims 1 to 5, characterized in that the movable body is held by the slide member and comprises a flat plate-shaped leaf spring positioned on the first direction side of the elastic piece.

7. The movable body comprises a flat plate-shaped leaf spring positioned on the first direction side of the elastic piece, If the direction perpendicular to the axial direction of the feed screw shaft and the first orthogonal direction is defined as the second orthogonal direction, The slide member has wall portions that connect to the nut holding portion, rise from the nut holding portion toward the third direction, and are arranged on both sides of the elastic piece portion in the second orthogonal direction. The linear drive device according to claim 3, characterized in that the leaf spring is held by the wall and is positioned on the first direction side of the third direction side portion of the elastic piece.

8. The linear drive device according to any one of claims 1 to 5 or claim 7, wherein the object to be driven is used in a head-up display device comprising a reflective mirror and a display unit that emits display light toward the reflective mirror, and the reflective mirror is fixed to a mirror holding member that is rotatably held on the frame of the head-up display device.

9. The linear drive device according to claim 8 and the mirror holding member are provided, A head-up display device characterized in that the first contact portion of the engaging portion, which is the part that contacts the support portion, and the second contact portion of the engaging portion, which is the part that contacts the elastic piece portion, are formed in a convex curved shape.

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