jacking device

Abstract

The application provides a jacking device and belongs to the technical field of automobile safety, and specifically comprises a piston assembly, a sleeve fixed on a vehicle body, and a piston rod axially movable in the sleeve, the sleeve has an opening at one end, the piston rod comprises an ejection end and an action end, and the ejection end is close to the opening in an initial installation state; a detonation unit is arranged inside the other end of the sleeve and is circumferentially closed with the sleeve, the gas outlet end of the detonation unit is opposite to the action end, the detonation unit is used for receiving an ignition signal sent by a controller and detonating to generate an action fluid, wherein the sleeve is further provided with a locking part, a clamping part is arranged on the piston rod close to the action end, the detonation unit is detonated to push the piston rod to move outward along the opening as a whole, and in the moving path of the piston rod, the clamping part is embedded with the locking part to prevent the piston rod from resetting and retracting. Through the processing scheme, even if affected by the hood pressure and its own gravity after detonation, the piston can still maintain the extended state and not retract into the jacking device.

Description

Technical Field

[0001] This invention relates to the field of automotive safety technology, and more specifically to a lifter. Background Technology

[0002] In car accident safety, it's crucial to minimize not only the potential injury to the driver but also to the pedestrian. When a car collides head-on with a pedestrian, the pedestrian's head may strike the hood again, causing secondary injury. To avoid this, current designs use a lift mechanism to instantly raise the hood to a designed height, cushioning the impact force when a pedestrian falls onto the hood and reducing head injuries. However, after the lift mechanism's piston detonates, it retracts due to the pressure from the hood and the pedestrian's own weight, thus failing to provide protection. Summary of the Invention

[0003] Therefore, in order to overcome the shortcomings of the prior art, the present invention provides a lifter in which the piston can remain extended and not retract into the lifter even after ignition, despite being affected by the pressure of the engine cover and its own weight.

[0004] To achieve the above objectives, the present invention provides a lifter for raising an engine hood, comprising: a piston assembly including a sleeve fixed to the vehicle body and a piston rod axially movable within the sleeve, one end of the sleeve having an opening, and the piston rod including an ejector end and an actuating end, wherein in the initial installation state, the ejector end is close to the opening; and an ignition unit disposed inside the other end of the sleeve, circumferentially closed with the sleeve, its outlet end opposite the actuating end, for receiving an ignition signal from a controller and generating actuating fluid upon ignition, wherein the sleeve is further provided with a locking element, and the piston rod has a locking portion near the actuating end, wherein the ignition unit ignites, pushing the piston rod as a whole to move outward along the opening, and the locking portion engages with the locking element along its movement path to prevent the piston rod from retracting.

[0005] In one embodiment, the actuating end extends radially outward along the piston rod to form a first protrusion, which is circumferentially closed with the sleeve. The locking part is a second protrusion spaced axially from the piston rod. There is a gap between the second protrusion and the sleeve. The locking member is fixed inside the sleeve and has a tubular structure. The ejector end extends through the locking member toward the opening. The detonation unit detonates, pushing the piston rod as a whole to move outward along the opening. The first and second protrusions enter the tube wall of the locking member. The first protrusion squeezes the end of the tube wall of the locking member, causing part of the tube wall of the locking member to undergo plastic deformation and enter between the first and second protrusions. The plastic deformation can abut against the lower part of the second protrusion, preventing the piston rod from retracting.

[0006] In one embodiment, the locking member has a bend in the tube wall toward its axis, such that when the end of the tube wall is squeezed by the first boss, a portion of the tube wall around the bend undergoes plastic deformation and enters between the first boss and the second boss.

[0007] In one embodiment, the locking member has a plurality of elastic claws on its tube wall. The side of the elastic claws near the opening includes a movable end that extends radially outward along the tube wall of the locking member and away from the opening. The plurality of elastic claws are press-fitted against the inner wall of the sleeve to fix the locking member inside the sleeve.

[0008] In one embodiment, the locking member is sleeved on the top of the outer side of the sleeve and has a plurality of circumferentially distributed locking feet. The locking feet extend radially inward along the sleeve and away from the opening. The ejector end passes through the opening and the plurality of locking feet and extends outward. The locking part is a locking tooth arranged circumferentially around the piston rod. When the detonation unit detonates, it pushes the piston rod as a whole to move outward along the opening. The plurality of locking feet can be embedded in the locking teeth to prevent the piston rod from retracting.

[0009] In one embodiment, the locking teeth are helical teeth, having an inclined first surface and a second surface perpendicular to the circumferential direction of the piston rod, the second surface abutting and engaging with the end of the locking foot.

[0010] In one embodiment, the piston rod is provided with an annular groove near the opening end, and when the piston is not moving, a plurality of the locking feet are engaged in the annular groove.

[0011] In one embodiment, the locking element includes a bracket, several balls, and a bushing. The bracket is fixed to the top of the outer side of the sleeve. The protruding end extends outward after passing through the opening and the central hole of the bracket. Several vertical grooves for accommodating the balls are provided on the side of the bracket near the piston rod. The bushing is disposed on the top of the bracket to prevent the balls from moving out of the grooves. The locking part is an arc-shaped groove extending inward around the piston rod. When the detonation unit is not detonated, the balls are located at the top of the vertical grooves and abut against the sleeve, the bracket, and the bushing, respectively. When the detonation unit is detonated, it pushes the piston rod as a whole to move outward along the opening until the arc-shaped groove moves to the vertical groove. The balls slide down to the bottom of the vertical groove and abut against the end of the arc-shaped groove, locking and preventing the piston rod from retracting.

[0012] In one embodiment, the gap between the vertical groove and the piston rod gradually decreases from the portion farther from the opening to the portion closer to the opening.

[0013] In one embodiment, the gap between the bushing and the support is smaller than the diameter of the sphere.

[0014] Compared with the prior art, the advantages of the present invention are: the piston rod and the sleeve are fixedly connected by the locking component on the sleeve and the locking part on the piston rod, which prevents the piston rod from moving downward and retracting, keeps the piston in the raised state, and keeps the engine cover in the raised state. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the cross-sectional structure of the lifting device in one embodiment of the present invention;

[0017] Figure 2 a is a schematic diagram of the initial state of the lifter in one embodiment of the present invention. Figure 2 b is a schematic diagram of the intermediate state of the lifter in one embodiment of the present invention. Figure 2 c is a schematic diagram of the final state of the lifter in one embodiment of the present invention;

[0018] Figure 3 This is an exploded view of the lifting device in one embodiment of the present invention;

[0019] Figure 4This is a schematic diagram of the cross-sectional structure of the lifting device in another embodiment of the present invention;

[0020] Figure 5 a is a schematic diagram of the initial state of the lifter in another embodiment of the present invention. Figure 5 b is a schematic diagram of the final state of the lifter in another embodiment of the present invention;

[0021] Figure 6 This is an exploded view of the lifting device in another embodiment of the present invention;

[0022] Figure 7 This is a schematic diagram of the cross-sectional structure of the lifting device in another embodiment of the present invention;

[0023] Figure 8 a is a schematic diagram of the initial state of the lifter in another embodiment of the present invention. Figure 8 b is a schematic diagram of the intermediate state of the lifter in another embodiment of the present invention. Figure 8 c is a schematic diagram of the final state of the lifter in another embodiment of the present invention;

[0024] Figure 9 This is an exploded view of the lifting device in another embodiment of the present invention. Detailed Implementation

[0025] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0026] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0028] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0029] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the aspects can be practiced without these specific details.

[0030] like Figure 1 As shown, this application embodiment provides a lifter for raising an engine hood. The lifter includes an ignition unit and a piston assembly. The lifter can be fixed to a vehicle via a mounting bracket 6. The piston assembly can be fixed to the vehicle via the mounting bracket 6. The piston assembly has a sleeve 5 and a piston rod 4 disposed within the sleeve and axially movable within the sleeve.

[0031] The sleeve 5 has a cylindrical structure. An opening at the upper end of the sleeve 5 allows the piston rod 4 to extend. A rubber cap 1 is provided at the upper end of both the sleeve 5 and the piston rod 4, covering the opening of the sleeve 5 and the piston rod 4. The sleeve also has a locking element 3.

[0032] Both the piston rod 4 and the detonation unit 11 are housed inside the sleeve 5. The piston rod includes an ejector end 410 and an actuating end 420. In the initial installation state, the ejector end 410 is close to the opening of the sleeve 5; the actuating end 420 is close to the detonation unit 11. The bottom of the piston rod 4 is circumferentially closed with respect to the inner wall of the sleeve 5, while the remaining portion may have a certain gap, which allows the piston rod 4 to move upward smoothly and, when in the ejector position, interacts with the opening to prevent the piston rod 4 from flying out of the sleeve 5 as a whole. A sleeve 2 may also be provided at the upper end of the piston rod 4 and the inner wall of the sleeve 5. The sleeve 2 can ensure the airtightness between the piston rod 4 and the sleeve 5 and provide guidance for the ejector end. In one embodiment, a sealing ring 7 is provided between the lower part of the piston rod 4 and the inner wall of the sleeve 5 to further ensure the airtightness of both. A locking part is provided on the piston rod 4 near the actuating end 420.

[0033] The ignition unit, located inside the other end of the sleeve 5, is circumferentially enclosed with the sleeve 5. Its outlet end faces the actuating end. It receives the ignition signal from the controller and, upon ignition, generates actuating fluid that causes the piston rod 4 to move axially within the sleeve 5. The ignition unit includes a cartridge 8, an igniter 9, a wiring harness 10, and an igniter base 11. The igniter 9 is fixed to the upper end of the igniter base 11. The igniter 9 may contain heat-sensitive material and extends from the lifting device through the wiring harness 10. The other end of the wiring harness 10 is connected to the ECU of the vehicle pedestrian frontal collision protection system. The cartridge 8 is located at the upper end of the igniter 9 and contains a gas-generating propellant. The gas-generating propellant can be a pyrotechnic powder, composed of nitroguanidine, pentaaminotetrazole, guanidine nitrate, potassium nitrate, potassium perchlorate, basic copper nitrate, and other additives. When the igniter 9 detonates, the gas-generating propellant burns rapidly, producing a large amount of non-toxic and harmless gas.

[0034] When the detonation unit detonates, the actuating fluid generated after detonation pushes the piston rod 4 outward along the opening. Along its movement path, the locking part engages with the locking element 3 to prevent the piston rod from retracting. The locking element 3 can be fixed to the inner wall of the sleeve or integrally formed with the sleeve; conversely, the locking part can be separately machined on the piston rod or integrally formed with the piston rod 4.

[0035] The aforementioned device achieves a fixed connection between the piston rod and the sleeve through a locking component on the sleeve and a locking part on the piston rod, preventing the piston rod from retracting and maintaining the piston in a raised state, thus keeping the hood in a raised state.

[0036] like Figure 2 As shown in b, in one embodiment, the actuating end 420 extends radially outward along the piston rod to form a first boss 41, which is circumferentially closed with the sleeve 5. The locking part is a second boss 42 that is axially offset along the piston rod 4, and there is a circumferential gap between the second boss 42 and the sleeve 5.

[0037] The locking element 3 is fixed inside the sleeve and has a tubular structure, with the protruding end 410 extending through the locking element toward the opening. In one embodiment, the locking element 3 can be fixed at one end to the inner wall of the sleeve 5, or it can be press-fitted inside the sleeve 5 by a tool.

[0038] The detonation unit detonates, pushing the piston rod 4 to move outward along the opening. The second protrusion 42 enters the interior of the locking member 3's tube wall, while the first protrusion 41 presses against the end of the locking member 3's tube wall, causing a portion of the locking member's tube wall to undergo plastic deformation and enter between the first protrusion 41 and the second protrusion 42. In one embodiment, the plastic deformation can abut against the lower part of the second protrusion 42, preventing the piston rod from retracting.

[0039] In the aforementioned device, the locking element provides axial support force to the first boss through plastic deformation, preventing the piston rod from retracting and returning to its original position.

[0040] In one embodiment, the locking member 3 has a bend 31 on its tube wall in the direction of its axis. The bend 31 causes a portion of the tube wall around the bend to plastically deform and enter between the first and second protrusions when the end of the tube wall is pressed by the first protrusion.

[0041] The angle of the bend can be an obtuse angle. The bend 31 can be convex towards the piston rod 4 or concave away from the piston rod 4. Under external force, the spring can deform at the bend 31. In one embodiment, the bend is set at 1 / 2 to 2 / 3 of the total length of the spring. The bend is set at the end of the spring away from the second position.

[0042] The aforementioned device provides a stress point for plastic deformation at the bend angle, facilitating the formation of a structure that locks the second boss.

[0043] like Figure 2 As shown in b, in one embodiment, the locking member 3 has a plurality of elastic claws 32 on its tube wall, with the elastic claws 32 located near the opening. Each elastic claw 32 includes a movable end that extends radially outward along the tube wall of the locking member 3 and away from the opening. The plurality of elastic claws are press-fitted against the inner wall of the sleeve 5 to fix the locking member 3 inside the sleeve.

[0044] like Figure 1 and Figure 2 As shown in Figure a, during the assembly of the jacking device, a locking element 3 is press-fitted into the inside of the sleeve 5 using a tooling. For example... Figure 3 As shown, the locking member 3 can be a tubular structure, and its thickness can be no greater than 1.5 mm. When the lifting device is working, the piston rod 4 moves vertically upward under the thrust. During the movement of the piston rod 4, the first boss 41 and the second boss 42 successively contact the locking member 3. When the piston rod 4 moves vertically upward, the first boss 41 can contact the inner wall of the locking member 3. In one embodiment, the gap size is 1 to 1.3 times the thickness of the locking member 3.

[0045] Then, as Figure 2 As shown in b, the first boss 41 is in contact with the lower end of the locking member 3, and at this time, the first boss 41 of the piston rod 4 is still a certain distance from the upper end of the locking member 3.

[0046] like Figure 2 As shown in Figure c, under the immense thrust, piston rod 4 continues to move upward, causing locking member 3 to undergo plastic deformation along the bend. Finally, piston rod 4 pushes locking member 3 and sleeve 2 together to the top of sleeve 5 and stops. Locking member 3 undergoes plastic deformation after being impacted by piston rod 4, jamming inside sleeve 5 and preventing piston rod 4 from moving downward, thus maintaining piston rod 4 in an upward-lifted state.

[0047] like Figure 4 , Figure 5 a, Figure 5 As shown in b, in one embodiment, the locking member 14 is fitted onto the top of the outer side of the sleeve 5. Figure 5 a and Figure 6 As shown, the locking member 14 has a plurality of circumferentially distributed locking feet 141, which extend radially inward along the sleeve and away from the opening. The ejector end 133 of the piston rod 13 passes through the opening and the plurality of locking feet and extends outward.

[0048] The locking portion consists of locking teeth arranged circumferentially around the piston rod. The locking portion may consist only of locking teeth 132 arranged around the piston. The locking teeth 132 are located on the piston rod 13 near the actuating end 134. In one embodiment, such as... Figure 6 As shown, the piston rod near the opening end is also provided with an annular groove 131. When the piston is not moving, several locking feet 141 are engaged in the annular groove 131. The upper end of the sleeve 5 is provided with an opening that allows the piston rod 13 to extend. A rubber cap 12 is provided at the upper end of the sleeve 5 and the piston rod 4, which can cover the opening of the sleeve 5 and the piston rod 13.

[0049] When the piston is not moving, the locking member 14's locking foot is located in the annular groove 131 of the piston rod 13; when the detonation unit detonates and pushes the piston rod to move outward along the opening, the locking member 14's locking foot 141 is located in the locking teeth 132 of the piston rod 13, preventing the piston rod from retracting. In some embodiments, the diameter of the circle at the end of the locking foot 141 is smaller than the diameter of the piston rod, but larger than the diameter of the circle at the bottom of the annular groove 131.

[0050] like Figure 4 and Figure 5As shown in Figure a, a locking element 14 is installed above the sleeve 5 of the jacking device. When the jacking device is not in operation, the locking element 14 is located within the annular groove 131 of the piston rod 13, and the locking element 14 is in its natural state. When the jacking device is in operation, the piston rod 13 moves vertically upward under the action of thrust, and the piston rod 13 opens the latch on the locking element 14, causing the locking element 14 to undergo elastic deformation. Figure 5 As shown in b, when the piston rod 13 moves to the top of the sleeve 5, it stops. At this time, the locking foot 141 of the locking member 14 is in the area where the locking tooth 132 of the piston rod 13 is located. The locking member 14 presses against the locking tooth 132 on the piston rod 13, preventing the piston rod 13 from moving downward and keeping the piston rod 13 in the raised state.

[0051] The locking teeth 132 can be arranged perpendicularly to the piston rod 13 or at an angle. In one embodiment, the locking teeth are helical teeth, having an inclined first surface and a second surface perpendicular to the circumference of the piston rod, the second surface abutting and engaging with the end of the locking foot. The locking teeth 132 are inclined on the piston rod 13, with the inclination direction being upward. This not only facilitates the movement of the piston rod 13 to the top of the sleeve 5, but also, when the locking foot of the locking member 14 is within the area of ​​the locking teeth 132 on the piston rod 13, the deformation direction of the locking foot 141 of the locking member 12 is opposite to the locking direction of the locking teeth 132, further preventing the piston rod 13 from moving downward.

[0052] like Figure 7 and Figure 8 As shown in Figure a, in one embodiment, the locking element includes a bracket 19, a plurality of balls 18, and a bushing 15. The bracket 19 is fixed to the top of the outer side of the sleeve 5. Figure 7 and Figure 9 As shown, the upper end of the sleeve 5 has an opening that allows the piston rod 16 to extend. The protruding end of the piston rod 16 extends outward after passing through the opening and the central hole of the bracket 19, as shown. Figure 8 As shown in Figure a, the support 19 has several vertical grooves 191 on the side near the piston rod to accommodate the ball. A bushing 15 is provided on the top of the support 19 to prevent the ball from moving out of the groove. A rubber cap 17 is provided at the upper end of the sleeve 5 and the piston rod 16, which can cover the opening of the sleeve 5 and the piston rod 16.

[0053] like Figure 7 As shown, the locking portion is an arc-shaped groove 161 extending inward around the piston rod 16. The piston rod 16 includes an ejector end 162 and an actuating end 163. The arc-shaped groove 161 is provided in the region where the actuating end 163 is located.

[0054] In one embodiment, the gap between the bushing 15 and the bracket 19 is smaller than the diameter of the ball 18. When the piston moves upward to its maximum stroke, the ball falls into the groove, thereby preventing the piston from retracting.

[0055] like Figure 7and Figure 8 As shown in Figure a, a bracket 19 is installed above the jacking device. Several vertical grooves 191 for accommodating balls are provided on the side of the bracket 19 near the piston rod. Multiple balls 18 are placed in the vertical grooves of the bracket 19. The balls 18 can be small metal balls, and the number can be more than two, such as eight. When the jacking device is not in operation, the lower surface of the balls 18 contacts the top surface of the vertical grooves 191 of the bracket 19, and the inner side of the balls 18 contacts the bushing 15 at the top of the piston rod 16. The gap between the bushing 15 and the bracket 19 is smaller than the diameter of the balls 18, and the balls are fixed to the upper part of the bracket 19. When the detonation unit is not detonated, the balls 18 are located at the top of the vertical grooves, abutting against the sleeve 5, the bracket 19, and the bushing 15, respectively.

[0056] like Figure 8 As shown in Figure b, when the lifting device is working, the piston rod 16 moves vertically upward under the thrust. The lower part of the piston rod 16 has an inwardly contracting arc-shaped groove 161. When the piston rod 16 moves to the top of the sleeve 5, the arc-shaped groove is inside the ball 18. The gap between the piston rod 16 and the support 19 is greater than the diameter of the ball 18. Under the action of gravity, the ball 18 falls into the lower part of the support 19. The detonation unit detonates, pushing the piston rod as a whole to move outward along the opening until the arc-shaped groove 161 moves to the vertical slide groove. The ball slides downward to the bottom of the vertical slide groove and abuts against the end of the arc-shaped groove, preventing the piston rod from retracting.

[0057] like Figure 8 As shown in Figure c, when the piston rod 16 sinks, it is restricted by the ball 18 and cannot continue to move downward, thus maintaining the lifting state.

[0058] In one embodiment, the gap between the vertical slide and the piston rod gradually decreases from the portion farther from the opening to the portion closer to the opening.

[0059] In the above embodiments, since the specific structures of the locking member and the locking part are different, the associated structural numbers are also different. For example, in Figure 1 Piston rod 4 in Figure 4 Piston rod 13 and Figure 7 Piston rod 16 in the middle.

[0060] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A lifter for raising a hood, characterized in that, include: A piston assembly includes a sleeve fixed to a vehicle body and a piston rod axially movable within the sleeve. One end of the sleeve has an opening, and the piston rod includes an ejector end and an actuating end. In the initial installation state, the ejector end is close to the opening. The ignition unit is located inside the other end of the sleeve, circumferentially enclosed with the sleeve. Its outlet end is opposite to the actuating end. It is used to receive the ignition signal from the controller and generate the actuating fluid after ignition. The sleeve is also provided with a locking element, and the piston rod is provided with a locking part near the working end. When the detonation unit detonates, it pushes the piston rod to move outward along the opening. On its movement path, the locking part engages with the locking element to prevent the piston rod from resetting and retracting. The actuating end extends radially outward along the piston rod to form a first boss, which is circumferentially closed with the sleeve. The locking portion is a second boss that is axially offset from the piston rod. There is a gap between the second boss and the circumferential of the sleeve. The locking member is fixed inside the sleeve and has a tubular structure. The ejector end extends through the locking member toward the opening. The detonation unit detonates, pushing the piston rod to move outward along the opening. The second protrusion enters the tube wall of the locking member, and the first protrusion squeezes the end of the tube wall of the locking member, causing a part of the tube wall of the locking member to undergo plastic deformation and enter between the first protrusion and the second protrusion. The plastic deformation can abut against the lower part of the second protrusion, preventing the piston rod from resetting and retracting.

2. The lifting device according to claim 1, characterized in that, The locking member has a bend in the tube wall towards its axis, so that when the end of the tube wall is squeezed by the first boss, part of the tube wall around the bend plastically deforms and enters between the first boss and the second boss.

3. The lifting device according to claim 1, characterized in that, The locking member has a plurality of elastic claws on its tube wall. The side of the elastic claws near the opening includes a movable end that extends radially outward and away from the opening along the tube wall of the locking member. The plurality of elastic claws are press-fitted against the inner wall of the sleeve to fix the locking member inside the sleeve.

Images