Mechanism for electrically adjusting linear movement of steering column

Abstract

The utility model discloses an electric adjusting steering column linear moving mechanism, which belongs to the technical field of automobile steering systems and comprises an upper column assembly, a lower column assembly, a power transmission system and a column limiting system. The pipe column limiting system comprises a guide groove formed in the outer surface of the upper pipe column sleeve, a limiting hole formed in the lower pipe column sleeve and a limiting block installed in the limiting hole, and the limiting block is matched with the guide groove and plays a role in guiding and supporting the upper pipe column sleeve; the power output of the motor drives the gear to rotate through transmission of the worm and the worm gear, the gear drives the cylindrical rack to do linear motion, the upper tubular column sleeve fixedly connected with the cylindrical rack is linearly adjusted relative to the lower tubular column sleeve, and the limiting block is matched with the guide groove to limit the linear motion range of the upper tubular column sleeve relative to the lower tubular column sleeve. The transmission system is better in rigidity, can adapt to severe and complex working conditions, solves the problems that a common rack is poor in transmission rigidity and easy to damage, and is controllable in adjustment length.

Description

Technical Field

[0001] The utility model relates to the technical field of automotive steering systems, and particularly relates to a linear movement mechanism for an electrically adjustable steering column. Background Art

[0002] The steering system is a series of devices used to change or maintain the driving or reversing direction of a vehicle. Among them, the steering column is used to connect the steering wheel and the steering gear, and is one of the important components of the automotive steering system. In the field of vehicle engineering, the steering column can adjust the position of the steering wheel up and down and back and forth within a certain range, so that the driver can conveniently change different spatial positions according to different needs to adapt to the driver's operating habits.

[0003] With the development of electrification and intelligence in the automotive industry, the use of electric steering columns has become increasingly common. However, at present, many large vehicles and engineering vehicles still use traditional manually adjustable steering columns. When engineering vehicles are working, the vibration is relatively large, which puts higher requirements on the stiffness and stability of the steering column. The existing electrically adjustable steering columns have poor rigidity and cannot well adapt to this working condition. In view of this, a linear movement mechanism for an electrically adjustable steering column applicable to engineering vehicles is designed, which has strong structural stability, good rigidity of the transmission system, and can adapt to harsh and complex working conditions. Summary of the Invention

[0004] Object of the Invention: To solve the problems of poor rigidity and weak stability of the length adjustment mechanism of the existing electric steering column, a linear movement mechanism for an electrically adjustable steering column applicable to engineering vehicles is provided.

[0005] Technical solution: The linear movement mechanism of the electric adjustable steering column of the present utility model includes an upper column assembly, a lower column assembly, a power transmission system, and a column limiting system. The upper column assembly includes an upper column sleeve and an upper transmission shaft installed inside the upper column sleeve. The lower column assembly includes a lower column sleeve and a lower transmission shaft installed inside the lower column sleeve. The upper column sleeve is sleeved inside the lower column sleeve, and the upper transmission shaft is connected to the lower transmission shaft through splines. The power transmission system includes a motor. The output shaft of the motor is connected to a worm, and the worm meshes with a worm gear. The worm gear is sleeved on a worm gear shaft. Gear one and gear two are respectively installed at both ends of the worm gear shaft. Gear one and gear two respectively mesh with rack one and rack two. The motor is fixed to the lower column sleeve through a motor mounting bracket, and the axis of the motor is arranged parallel to the axis of the steering column. Rack one and rack two are distributed on both sides of the upper column sleeve, and one end of rack one and rack two is fixed to the upper column sleeve, and the other end is free, and its length direction is arranged parallel to the direction of the steering column core. The column limiting system includes a guide groove provided on the outer surface of the upper column sleeve, a limiting hole provided on the lower column sleeve, and a limiting block installed in the limiting hole. The limiting block cooperates with the guide groove to guide and support the upper column sleeve. The power output of the motor drives the gears to rotate after being transmitted by the worm and the worm gear. The gears drive the rack to move linearly, so that the upper column sleeve fixedly connected to the rack is linearly adjusted relative to the lower column sleeve. The limiting block is engaged with the guide groove to limit the linear movement range of the upper column sleeve relative to the lower column sleeve.

[0006] To further improve the above technical solution, the upper column sleeve and the lower column sleeve are integrally cast. The upper column sleeve is a hollow tubular structure, and its inner surface is fitted with the upper transmission shaft through a bearing and is integrally sleeved inside the lower column sleeve. The lower column sleeve is fitted with the lower transmission shaft through a bearing.

[0007] Furthermore, a shoulder for installing a bearing is provided on the inner side of the head of the upper column sleeve, and an installation groove for fixing the rack is provided on the upper surface of the outer side of the head. The upper surface of the head of the lower column sleeve is provided with a motor bracket installation platform, and a shoulder for installing a bearing is provided on the inner side of the tail. The limiting hole is provided on the installation platform.

[0008] Furthermore, the upper transmission shaft has a solid head and a hollow tail structure. The head is provided with a thread and splines for connecting the steering wheel, and the tail is provided with splines for connecting the lower transmission shaft. The lower transmission shaft has a solid head and a hollow tail structure. The head is provided with splines for connecting the vehicle steering gear, and the outer side of the tail is provided with splines for connecting the upper transmission shaft.

[0009] Furthermore, a shaft collar is provided on the inner side of the bearing of the upper transmission shaft and the lower transmission shaft, and a bearing retaining ring is provided on the outer side to limit the axial movement of the upper transmission shaft and the lower transmission shaft.

[0010] Further, a guiding hole is provided on the lower pipe string sleeve to support and guide the cylindrical rack passing through the guiding hole.

[0011] Further, a tooth groove is formed on the upper surface of the cylindrical rack for cooperating with a gear. The head is machined into a cuboid and has a hole in the middle for cooperating with the installation groove on the upper surface of the upper pipe string sleeve, and the cooperating part is fixed by a cylindrical rack bolt.

[0012] Further, a spring is sleeved on the limiting block and is in contact cooperation through a spring cover on the outer end face of the limiting block. By tightening or loosening the spring cover, the force applied to the spring is changed, thereby changing the frictional force between the limiting block and the guiding groove.

[0013] Further, the limiting block is made of nylon material, and its bottom surface is matched with the surface of the guiding groove.

[0014] Beneficial effects: Compared with the prior art, the advantages of the present utility model are as follows: The upper and lower transmission shafts sleeved in the upper and lower pipe string sleeves of the present utility model are connected by splines, and bearings are installed at both ends to ensure axial positioning; the motor is used as the power source, the motor drives the worm, and the worm and worm gear are for speed reduction and torque increase. A gear is installed on the worm gear shaft, and the gear meshes with the cylindrical rack. One end of the cylindrical rack is fixed to the upper pipe string sleeve and the other end is free. The length direction of the cylindrical rack is arranged parallel to the direction of the steering column tube core. The cylindrical rack is driven by the gear to move, thereby pushing the steering column to perform a linear reciprocating motion. Compared with the structure using ordinary rack transmission, the transmission system has better rigidity, can adapt to harsh and complex working conditions, solves the problems of poor rigidity and easy damage of ordinary rack transmission, and the adjustable length is controllable; the mechanism structure is simple, the manufacturing and installation difficulty is reduced, and the cylindrical rack is convenient to disassemble, install, overhaul and replace. The use of the guiding groove and the limiting block improves the stability of the cooperation; the cylindrical rack transmission is adopted. Brief Description of the Drawings

[0015] Figure 1 is an overall schematic diagram of a linear movement mechanism of an electric adjustable steering column proposed by the present utility model;

[0016] Figure 2 is a front view of a linear movement mechanism of an electric adjustable steering column;

[0017] Figure 3 is a top view of a linear movement mechanism of an electric adjustable steering column;

[0018] Figure 4 is Figure 2 the A-A sectional view in

[0019] Figure 5 is Figure 3 the B-B sectional view in

[0020] Figure 6 is Figure 4 a partially enlarged view of No. 6 in the figure;

[0021] Figure 7 is a schematic structural diagram of the power transmission part;

[0022] Figure 8 is a schematic diagram of the cooperation between a gear and a cylindrical rack;

[0023] Figure 9 is a schematic structural diagram of a worm gear shaft;

[0024] Figure 10 is a schematic structural diagram of a lower pipe string sleeve;

[0025] Figure 11 is a schematic structural diagram of an upper pipe string sleeve;

[0026] Figure 12 is a schematic structural diagram of a motor mounting bracket.

[0027] The numbers in the figure are: 1, upper pipe string assembly; 101, upper transmission shaft; 102, upper pipe string sleeve; 2, lower pipe string assembly; 201, lower transmission shaft; 202, lower pipe string sleeve; 3, power transmission system; 301, motor; 302, worm; 303, worm gear; 304, worm gear shaft; 305, gear one; 306, cylindrical rack one; 307, cylindrical rack bolt; 308, gear fixing nut; 309, worm gear shaft sleeve; 310, motor mounting bracket; 311, rack guide platform; 312, gear two; 313, cylindrical rack two; 314, rack guide platform; 401, left bracket of worm gear shaft; 402, right bracket of worm gear shaft; 501, left bearing of worm gear shaft; 502, right bearing of worm gear shaft; 503, bearing of lower transmission shaft; 504, bearing of upper transmission shaft; 505, lower bearing retaining ring; 506, upper bearing retaining ring; 6, limit hole; 601, limit block; 602, spring; 603, spring cover; 604, guide groove. Specific embodiments

[0028] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings, but the protection scope of the present invention is not limited to the described embodiments.

[0029] Embodiment 1: As shown in Figures 1 to 12 the electric adjustment steering column linear movement mechanism shown, which includes an upper pipe string assembly 1, a lower pipe string assembly 2, a power transmission system 3 and a pipe string limiting system.

[0030] The upper pipe column assembly 1 includes an upper pipe column sleeve 102 that provides external support and guidance, and an upper transmission shaft 101 installed inside the upper pipe column sleeve 102 to play a role in connection and transmission. The lower pipe column assembly 2 includes a lower pipe column sleeve 202 that provides external support and guidance, and a lower transmission shaft 201 installed inside the lower pipe column sleeve 202 to play a role in connection and transmission.

[0031] The power transmission system includes a motor 301 installed on a motor mounting bracket 310, the motor mounting bracket 310 fixed to the upper plane of the lower pipe column sleeve 202, a worm 302 installed inside the motor mounting bracket 310, a worm gear 303 meshing with the worm 302, a worm gear shaft 304, a first gear 305 installed at one end of the worm gear shaft 304, a first cylindrical rack 306 meshing with the first gear 305, a second gear 312 installed at the other end of the worm gear shaft 304, and a second cylindrical rack 313 meshing with the second gear 312.

[0032] The pipe column limit system includes a guide groove 604 on the outer surface of the upper pipe column sleeve 102, a limit hole 6 on the outer surface of the lower pipe column sleeve 202, a limit block 601 that cooperates with the limit hole and the guide groove 604, a spring 602 installed in the limit hole, and a spring cover 603.

[0033] The upper transmission shaft 101 is connected to the steering wheel, and the lower transmission shaft 201 is connected to the vehicle steering gear. The two are connected by a spline. The upper transmission shaft 101 is a hollow tubular structure inside. The end connected to the steering wheel is solid, and the other end is hollow. The spline groove is inside its rear end. The lower transmission shaft 201 is also a hollow tubular structure inside. The end connected to the steering gear is solid, and the other end is hollow. The spline groove is outside its rear end.

[0034] As Figure 4 shown, the upper transmission shaft 101 is sleeved inside the upper pipe column sleeve 102. The two are coaxially arranged and connected and fixed by an upper transmission shaft bearing 504. The positioning and fastening of the bearing rely on a collar and a bearing retaining ring 506 provided on the upper transmission shaft 101. The upper transmission shaft 101 can rotate freely to transmit rotational motion to the lower transmission shaft 201.

[0035] As Figure 1 and Figure 2As shown in the figure, the upper pipe column sleeve 102 is sleeved inside the lower pipe column sleeve 202. A rack mounting groove is provided on the upper surface of its head, and bolt holes are opened in the mounting groove. The head of the cylindrical rack 306 is perforated and fixed in the mounting groove using the cylindrical rack bolt 307. When the rack is driven by the gear to move back and forth, the upper pipe column assembly 1 is also driven to move back and forth to achieve length adjustment. There is an integrally formed mounting platform on the lower surface of the head of the lower pipe column sleeve 202. Mounting limit holes are provided on the platform. The lower transmission shaft 201 is sleeved inside the lower pipe column sleeve 202, and the two are coaxially arranged and connected and fixed through the lower transmission shaft bearing 503. The positioning and fastening of the bearing rely on the collar and bearing retaining ring 505 provided on the lower transmission shaft 201. When the upper transmission shaft 101 rotates, the lower transmission shaft 201 also rotates accordingly. When the upper pipe column assembly 1 makes a linear movement, the meshing length of the splines between the upper and lower transmission shafts also changes accordingly.

[0036] As Figure 7 shown in the figure is the structural schematic diagram of the power transmission part. The motor 301 drives the worm 302 to rotate, and the worm 302 drives the worm wheel 303 to rotate. The motor 301 is installed on the motor mounting frame 310, and the worm wheel 303 is installed on the worm wheel shaft 304. As Figure 12 shown in the figure of the motor mounting frame 310, its bottom is designed with a platform for easy installation, and it is installed on the platform above the lower pipe column sleeve 202 and fixed with bolts. The worm 302 is coaxially installed in the hollow cylinder on the right side of the motor mounting frame 310, and bearing bushes are installed at both the head and the tail of the hollow cylinder to reduce wear.

[0037] As Figure 9 shown in the figure of the worm wheel shaft 304, it has a left-right symmetric structure. The worm wheel 303 and the worm wheel shaft 304 are connected by splines, and sleeves are installed on the worm wheel shafts on both sides of the worm wheel 304 to achieve axial positioning. The reduction mechanism is a worm and worm wheel mechanism composed of an engaged worm and worm wheel. The worm and worm wheel cooperate with each other to have a self-locking function, so that the steering wheel can be kept in the adjusted position, improving reliability and stability.

[0038] As Figure 5 shown in the figure, the left and right ends of the worm wheel shaft 304 are respectively installed on the left support 401 of the worm wheel shaft and the right support 402 of the worm wheel shaft. Round holes are opened on the worm wheel shaft supports for installing bearings. The round holes are coaxial with the worm wheel shaft 304. Shoulder shafts are provided at both ends of the worm wheel shaft to position the bearings. The bearing 501 is installed on the left side, and the bearing 502 is installed on the right side. Round holes are opened at the bottom and side of the left and right worm wheel shaft supports, and threaded holes are opened at the corresponding positions at the bottom and side of the lower pipe column sleeve 202, and the two are fixed together with bolts. The gear 305 is installed at the left end of the worm wheel shaft 304 and is coaxial with the worm wheel 303. The gear 305 meshes with the cylindrical rack 306. The cooperation schematic diagram of the gear 305 and the cylindrical rack 306 is as Figure 8As shown in the figure. The gear 305 and the worm shaft 304 are connected by a common flat key. There is a thread on the worm shaft to the left of the installation position of the gear 305, and it is fixed with a gear fixing nut 308. A worm shaft sleeve 309 is installed on the worm shaft between the gear 305 and the worm 303, which restricts the axial movement of the gear 305 and the worm 303.

[0039] A rack guide platform 311 is provided on the lower pipe column sleeve 202. A circular guide hole is provided above the guide platform, and a bearing bush is installed in the hole to reduce wear. The cylindrical rack 306 is coaxially arranged with the circular guide hole. The use of a cylindrical rack and a guide platform that cooperate with it to play a guiding and supporting role increases the stability and rigidity of the system. As Figure 7 shown, a tooth groove is opened from the tail to the middle near the head on the upper surface of the cylindrical rack for cooperation with the gear. The head is machined into a cuboid and has a hole in the middle. The head is fitted with the installation groove on the upper surface of the upper pipe column sleeve 102. The installation groove is also a cuboid and has a bolt hole on the bottom surface, and is fixed with a bolt 307. After the rack is installed, its axis is parallel to the direction of the steering column tube core.

[0040] As Figure 4 and Figure 6 shown, limit holes are opened on the upper and lower surfaces of the lower pipe column sleeve 202, and threads are provided on the inner surface of the holes. A guide groove 604 is engraved on the outer surface of the upper pipe column sleeve 102. A limit block 601 and a spring 602 are installed in the limit holes and sealed with a spring cover 603. The limit block 601 is made of nylon material. Its bottom surface is fitted with the profile surface of the guide groove 604, and the middle and upper parts are installed in the limit holes and restricted from moving. The spring 602 is installed in the groove of the limit block 601 and contacts and cooperates with the limit block and the spring cover. The outer surface of the spring cover 603 is provided with threads to cooperate with the limit holes. By tightening or loosening the spring cover 603, the force applied to the spring 603 is changed, thereby changing the supporting force of the limit block 601 on the upper pipe column sleeve 102. Grease is added to the holes to reduce the friction between the limit block 602 and the upper pipe column sleeve 102 and prevent rust at the same time. After using the limit block, the supporting force on the upper pipe column sleeve and the stability during linear movement are enhanced.

[0041] As Figure 10 and Figure 11 shown, a limit hole is added to both the front and rear sides of the lower pipe column sleeve 202, and a guide groove is added to both the front and rear sides of the upper pipe column sleeve 102. The parts and installation methods in the limit holes are the same as before. The designed limit block has a buffer and shock absorption function. After using four limit blocks, the radial stability of the upper pipe column sleeve 102 is greatly enhanced, and its rotation is also restricted. The radial position of the upper pipe column sleeve can be adjusted conveniently, making the rigidity and stability of the system better.

[0042] As Figure 1 and Figure 10As shown, another rack guide 314 is provided on the right side of the rack guide 311, and the two guides are symmetrically arranged. The right side surface of the rack guide 311 is flush with the right side surface of the lower pipe column sleeve 202. After setting two guides, the support for the cylindrical rack is enhanced, making the transmission system more stable during movement. At the same time, the meshing position of the gear and the cylindrical rack is between the two guides, and the force on the cylindrical rack is more evenly distributed than that of a single guide, reducing the force exerted by the cylindrical rack on the upper pipe column sleeve 102 and making the upper pipe column assembly more stable and less likely to deviate from the axis during movement.

[0043] Another set of gear-rack transmission system is provided on the other side of the pipe column. As Figure 5 、 Figure 7 shown, the second gear 312 is installed at the right end of the worm gear shaft 303, and the installation and positioning method are the same as that of the gear 305. The second gear 312 meshes with the second cylindrical rack 313. Two rack guides are also provided on the other side of the lower pipe column sleeve 202, and rack installation grooves are also provided at the corresponding positions of the upper pipe column sleeve 102. The installation method of the second cylindrical rack 313 is the same as that of the cylindrical rack 306. In this preferred solution, a single cylindrical rack drive is symmetrically designed and increased to two cylindrical rack drives. Compared with the original solution, the symmetry of the worm gear shaft structure is utilized, the transmission system is symmetrically arranged, and the spatial position is reasonably arranged; the forces at both ends of the worm gear shaft are balanced, and the transmission is smoother; the two symmetrically arranged transmission systems make the pipe column more stable during linear movement, and the system rigidity is also greatly improved.

[0044] The linear movement adjustment process of this electric steering pipe column is as follows: When the motor 301 is powered on and starts, it drives the worm 302 to move, and the worm drives the worm gear 302 to rotate. Since the worm gear is installed on the worm gear shaft 304, the movement of the worm gear shaft drives the gears 305 and 312 installed at both ends to rotate. The gears drive the cylindrical racks 306 and 313 to move linearly. The racks make a linear movement parallel to the axis of the pipe column core under the constraint of the guide holes and installation grooves, pushing the upper pipe column assembly to move, realizing the electric length adjustment function.

[0045] As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be construed as a limitation of the present invention itself. Various changes can be made in its form and details without departing from the spirit and scope of the present invention defined by the appended claims.

Claims

1. An electric adjustable steering column linear movement mechanism, comprising an upper column assembly (1), a lower column assembly (2), a power transmission system (3) and a column limiting system, characterized in that: The upper column assembly (1) includes an upper column sleeve (102) and an upper transmission shaft (101) installed inside the upper column sleeve (102). The lower column assembly (2) includes a lower column sleeve (202) and a lower transmission shaft (201) installed inside the lower column sleeve (202). The upper column sleeve (102) is sleeved inside the lower column sleeve (202), and the upper transmission shaft (101) is connected to the lower transmission shaft (201) through a spline; The power transmission system (3) includes a motor (301). The output shaft of the motor (301) is connected to a worm (302). The worm (302) meshes with a worm gear (303). The worm gear (303) is sleeved on a worm gear shaft (304). Gear one (305) and gear two (312) are respectively installed at both ends of the worm gear shaft (304). Gear one (305) and gear two (312) respectively mesh with a cylindrical rack one (306) and a cylindrical rack two (313); The motor (301) is fixed to the lower column sleeve (202) through a motor mounting bracket (310), and the axis of the motor (301) is arranged parallel to the axis of the steering column; The cylindrical rack one (306) and the cylindrical rack two (313) are distributed on both sides of the upper column sleeve (102), and one end of the cylindrical rack one (306) and the cylindrical rack two (313) is fixed to the upper column sleeve (102), and the other end is free, and its length direction is arranged parallel to the core direction of the steering column; The column limiting system includes a guide groove provided on the outer surface of the upper column sleeve (102), a limiting hole (6) provided on the lower column sleeve (202), and a limiting block (601) installed in the limiting hole (6). The limiting block cooperates with the guide groove to guide and support the upper column sleeve (102); The power output of the motor (301) drives the gear to rotate after being transmitted by the worm (302) and the worm gear (303). The gear drives the cylindrical rack to move linearly, so that the upper column sleeve (102) fixedly connected to the cylindrical rack is linearly adjusted relative to the lower column sleeve (202). The limiting block (601) is in contact and cooperation with the guide groove to limit the linear movement range of the upper column sleeve (102) relative to the lower column sleeve (202).

2. The linear movement mechanism of the power-adjustable steering column according to claim 1, wherein: The upper column sleeve (102) and the lower column sleeve (202) are integrally cast. The upper column sleeve (102) is a hollow tubular structure, and its inner surface cooperates with the upper transmission shaft (101) through a bearing, and the whole is sleeved inside the lower column sleeve (202). The lower column sleeve (202) cooperates with the lower transmission shaft (201) through a bearing.

3. The linear movement mechanism of the power-adjustable steering column according to claim 2, characterized in that: An axle shoulder (505) for installing a bearing is provided on the inner side of the head of the upper column sleeve (102), and an installation groove for fixing the cylindrical rack one (306) is provided on the upper surface of the outer side of the head; The upper surface of the head of the lower column sleeve (202) is provided with a motor bracket installation platform, and an axle shoulder for installing a bearing is provided on the inner side of the tail.

4. The linear movement mechanism of the power-adjustable steering column according to claim 1, characterized in that: The upper drive shaft (101) has a solid head and a hollow tail structure. The head is provided with threads and splines for connecting to the steering wheel, and the tail is provided with splines for connecting to the lower drive shaft (201); the lower drive shaft has a solid head and a hollow tail structure. The head is provided with splines for connecting to the vehicle steering gear, and the outer side of the tail is provided with splines for connecting to the upper drive shaft.

5. The linear movement mechanism of the power-adjustable steering column according to claim 1, characterized in that: Circlips (506) are provided inside the bearings of the upper drive shaft (101) and the lower drive shaft (201), and bearing retainers (504) are provided outside to limit the axial movement of the upper drive shaft (101) and the lower drive shaft (201).

6. The linear movement mechanism of the power-adjustable steering column according to claim 1, characterized in that: The lower column sleeve (202) is provided with a guide hole (311) to support and guide the cylindrical rack passing through the guide hole.

7. The linear movement mechanism of the power-adjustable steering column according to claim 1, characterized in that: The upper surface of the cylindrical rack one (306) is provided with tooth grooves for cooperating with the gear one (305). The head is machined into a cuboid and has a hole in the middle for cooperating with the installation groove on the upper surface of the upper column sleeve (102), and the cooperating part is fixed by a cylindrical rack bolt (307).

8. The linear movement mechanism of the power-adjustable steering column according to claim 1, characterized in that: A spring is sleeved on the limit block (601) and is in contact and cooperation through a spring cover (603) on the outer end surface of the limit block (601). By tightening or loosening the spring cover (603), the force exerted on the spring (602) is changed, thereby changing the frictional force between the limit block (601) and the guide groove (604).

9. The linear movement mechanism of the power-adjustable steering column according to claim 1, characterized in that: The limit block (601) is made of nylon material, and its bottom surface cooperates with the surface of the guide groove (604).

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