A locking type projection screen supporting device based on a hollow electromagnet

Abstract

The application discloses a locking type projection curtain supporting device based on a hollow electromagnet, which comprises a driving mechanism, a supporting mechanism and a fixing module; the driving mechanism is composed of a push rod, a rack, a fixed block and an incomplete gear; the supporting mechanism is composed of an upper supporting rod, a locking module, a lower supporting rod and a lower mounting block; and the fixing module is composed of an upper fixed plate and a curtain traction plate. Through the reciprocating movement of the push rod and the rack, the upper supporting rod is driven to rotate by the transmission of the gear and the rack, and the locking effect of the locking module is matched, so that the curtain can be stably supported at any hovering position, the use stability of the vehicle-mounted projection curtain is effectively improved, and the application has high practical value.

Description

Technical Field

[0001] This invention relates to the field of projection technology, and in particular to a locking projection screen support device based on a hollow electromagnet. Background Technology

[0002] In recent years, automotive projection screens have moved from aftermarket parts to mass production of automotive-grade components, forming three major technical routes: retractable screens, fixed screens, and screenless projection. Automotive projection screens are mainly used in rear-seat entertainment and in-car cinemas, but current automotive projector screens still have many unresolved shortcomings, including large screen space requirements, insufficient reliability of the retraction mechanism, vehicle swaying affecting the viewing experience during driving, unstable support, and inability to hover at any position.

[0003] CN121232516A discloses a vehicle projection screen, which includes a housing, a screen mechanism, and a support mechanism. The housing defines a housing space, the screen mechanism is located within the housing, and the support mechanism includes a first support rod, a second support rod, and a first driving member. Although this structure can provide support, it can only provide stable support when the support structure is fully extended, and it cannot be suspended at any position on the screen, thus limiting its application scenarios.

[0004] CN119928727A discloses a vehicle-mounted projection screen device and a vehicle-mounted projection system. The vehicle-mounted projection screen device includes: a screen fixing plate, a screen flipping arm, and a screen body. The screen flipping arm has a flipping arm mounting base and a flipping arm main rod. The screen body is a rigid screen and is fixedly connected to the flipping arm main rod. Although this structure is stable in use, its overall size is large, making it inconvenient to store and difficult to adapt to the limited space inside a vehicle.

[0005] CN120428504A discloses a stable projection screen, including a housing and a screen body. An automatic winding mechanism is connected to the top of the screen body, providing an upward winding force to retract the screen body into the housing. A support mechanism is located at the rear of the screen body and is symmetrically distributed about the left and right sides of the screen body. While this structure improves the stability of the screen during vehicle movement, the designed structure will reduce the space available for in-vehicle storage or headroom, indicating insufficient miniaturization. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, this invention provides a locking projection screen support device based on a hollow electromagnet, which achieves stable support, can be suspended at any position, and keeps the mechanism to a minimum size, thus meeting the invention objective of miniaturization design.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: The locking projection screen support device based on a hollow electromagnet, as described in this invention, is characterized by comprising a drive mechanism, a support mechanism, and a fixing module. The drive mechanism consists of a fixing bolt, a push rod, a rack, an incomplete gear, a fixing block, a fixing screw, and a first threaded hole. The push rod has a tail mounting hole and a head mounting hole, and is fixedly connected to an upper fixing plate using the tail mounting hole and the fixing bolt. The head mounting hole is fitted onto a cylinder, which is a component welded into a rectangular groove on the left side of the rack. The fixing block is mounted on the rack via a fixing screw that engages with the threaded first threaded hole. The lower left end of the rack restricts the axial movement of the push rod head along the cylinder, realizing the connection between the push rod and the rack; the rack meshes with an incomplete gear through a gear rack pair, converting the linear motion of the push rod into the rotational motion of the incomplete gear; the support mechanism includes an upper support rod, a lower support rod, a bushing, a lower mounting block, a first spline bushing, a support shaft, a second spline bushing, a support shaft stop, a lower support rod stop, an annular iron sheet, and a hollow electromagnet; the upper support rod head is provided with an upper support rod head keyway, the first spline bushing is provided with a first bushing keyway, and the second spline bushing is provided with a first bushing keyway. The bushing is provided with a second bushing keyway, and the keyway at the head of the upper support rod, the first bushing keyway, and the second bushing keyway all match the gear keyway; three keys are evenly distributed along the circumference of the support shaft, and the first spline bushing, the second spline bushing, the incomplete gear, and the upper support rod are all configured to cooperate with the support shaft through keyways to achieve synchronous rotation of the support shaft and the upper support rod; the tail of the upper support rod is provided with an upper support rod circular groove; the tail of the lower support rod is provided with a lower support rod circular groove; the left half of the hollow electromagnet is the attraction end, and the right half is the fixing end. The fixed end of the magnet is installed in the circular groove of the upper support rod with an interference fit; the adsorption end of the hollow electromagnet is installed in the circular groove of the lower support rod with a clearance fit; the annular iron sheet is embedded in the bottom of the circular groove of the lower support rod and attracts the adsorption end of the hollow electromagnet; the lower support rod stop and the through hole at the tail of the lower support rod form a clearance fit; the clearance fit between the hollow electromagnet and the circular groove of the lower support rod, and between the lower support rod stop and the lower support rod, realizes the relative rotation between the upper support rod and the lower support rod; the fixing module is composed of the upper fixing plate and the curtain traction plate.

[0008] The invention also features a locking projection screen support device based on a hollow electromagnet, wherein the push rod in the drive mechanism is installed inside a rectangular ring welded to the upper fixed plate, and two rectangular rings are provided; the upper surface of the rack is attached to the surface of the sliding groove, and the limiting effect of the sliding groove ensures that the rack moves linearly along the extension and retraction direction of the push rod without deflection; the incomplete gear has a gear keyway inside, and the gear keyway has three keyways evenly distributed around the circumference.

[0009] The locking projection screen support device based on hollow electromagnets in this invention is characterized in that the support shaft is installed between the first mounting holes and the second mounting holes on the left and right sides of the upper fixing plate through shaft hole cooperation, and the axial positioning of the support shaft is achieved by using a support shaft stop block fixed by bolts; the tail of the upper support rod has a second threaded hole, and the tail of the lower support rod has a through hole. The upper support rod, the hollow electromagnet and the lower support rod are axially fixed by the fixing action of fixing nuts, fixing bolts, second threaded holes and washers.

[0010] The locking projection screen support device based on hollow electromagnets in this invention is characterized in that the head of the lower support rod is connected to the lower mounting block by an internal hexagon bolt and is axially positioned by a bushing; the screen traction plate is fixedly connected to the lower mounting block by bolts.

[0011] The invention's locking projection screen support device based on hollow electromagnets is characterized by the fact that there are two of each of the drive mechanism, support mechanism, and upper fixing plate, which are symmetrically installed on both sides of the screen traction plate in the fixing module. The drive mechanisms on both sides move synchronously to ensure the consistency of movement of the support mechanisms on both sides. The upper fixing plate is bolted to the lower end of the vehicle or the projection screen housing. The screen traction plate is movably installed together with the projection screen. The above structure allows the screen to be easily extended and retracted.

[0012] The locking projection screen support device based on hollow electromagnets in this invention is characterized by the following: the upper support rod and the lower support rod are rotatably connected, and the hollow electromagnet is installed at the connection between the upper and lower support rods; a circular iron sheet is installed on the bottom surface of the circular groove of the lower support rod and is positioned opposite to the adsorption end; the contact surface between the circular iron sheet and the adsorption end is provided with a friction-enhancing coating; after the hollow electromagnet is energized and magnetized, the coating adheres tightly to the adsorption end of the hollow electromagnet, generating a frictional force sufficient to prevent relative rotation between the upper and lower support rods, thereby enabling the projection screen to be suspended and stabilized at any position.

[0013] Compared with existing technologies, the beneficial effects of this invention are reflected in: 1. This invention employs a small push rod and gear rack mechanism, which is compact in structure, occupies little space, and is easy to install. The gear rack structure has higher transmission efficiency, more efficient force transmission, and can ensure the accuracy of motion and a long service life.

[0014] 2. The present invention has designed a reasonable locking mechanism, which can realize the relative rotation between the upper and lower support rods, and can also lock the upper and lower support rods at any position, so as to suspend the projection screen at any position.

[0015] 3. The present invention is designed with two support rods, one above the other, which are staggered. Therefore, when the curtain is fully retracted, the upper and lower support rods will not overlap, thus ensuring the compactness of the structure.

[0016] 4. The present invention designs a reasonable keyway structure and support shaft structure, which ensures the consistency of movement between the incomplete gear and the upper support rod, improves the reliability of the overall movement of the mechanism, and can transmit a large torque. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0018] Figure 2 This is a schematic diagram of the drive mechanism structure in this invention.

[0019] Figure 3 This is a partial schematic diagram of the driving mechanism in this invention.

[0020] Figure 4 This is an exploded view of the connection point of the upper support rod in this invention.

[0021] Figure 5 This is an exploded view of the connection between the upper and lower support rods in this invention.

[0022] Figure 6 This is a schematic diagram of the folded state of the support device of the present invention.

[0023] The following components are labeled in the diagram: 101 Upper fixing plate, 1011 Rectangular ring, 1012 First mounting hole, 1013 Second mounting hole, 1014 Sliding groove, 102 Curtain traction plate, 201 Fixing bolt, 202 Push rod, 2021 Tail mounting hole, 2022 Head mounting hole, 203 Rack, 2031 Cylinder, 2032 Rectangular groove, 2033 First threaded hole, 204 Incomplete gear, 2041 Gear keyway, 205 Fixing block, 206 Fixing screw, 301 Upper support rod, 3011 Upper support rod head keyway, 3012 Upper support rod. Circular groove, 3013 second threaded hole, 302 fixing nut, 303 lower support rod, 3031 lower support rod circular groove, 304 socket head cap screw, 305 bushing, 306 lower mounting block, 307 first spline bushing, 3071 first bushing keyway, 308 support shaft, 309 second spline bushing, 3091 second bushing keyway, 310 support shaft stop, 311 bolt, 312 lower support rod stop, 313 circular iron sheet, 314 hollow electromagnet, 3141 adsorption end, 3142 fixing end, 315 washer, 316 fixing bolt. Detailed Implementation

[0024] The following description, in conjunction with the accompanying drawings, provides a further illustration of a locking projection screen support device based on a hollow electromagnet, according to the present invention.

[0025] See Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown, the locking projection screen support device based on hollow electromagnets in this example includes an upper fixing plate 101, a rectangular ring 1011, a first mounting hole 1012, a second mounting hole 1013, a sliding groove 1014, a screen traction plate 102, a fixing bolt 201, a push rod 202, a tail mounting hole 2021, a head mounting hole 2022, a rack 203, a cylinder 2031, a rectangular groove 2032, a first threaded hole 2033, an incomplete gear 204, a gear keyway 2041, a fixing block 205, a fixing screw 206, an upper support rod 301, and an upper support rod head. Keyway 3011, upper support rod circular groove 3012, fixing nut 302, lower support rod 303, lower support rod circular groove 3031, internal hex bolt 304, bushing 305, lower mounting block 306, first spline bushing 307, first bushing keyway 3071, support shaft 308, second spline bushing 309, second bushing keyway 3091, support shaft stop block 310, bolt 311, lower support rod stop block 312, annular iron sheet 313, hollow electromagnet 314, adsorption end 3141, fixing end 3142, washer 315, fixing bolt 316.

[0026] See Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 6As shown, for the drive mechanism, the push rod 202 outputs power to drive the rack 203 to move linearly. Through gear and rack meshing, the linear motion of the push rod 202 is converted into the rotational motion of the incomplete gear 204. The push rod 202 is connected to the upper fixed plate 101 by the fixing bolt 201. The head mounting hole 2022 of the push rod 202 is fitted onto the cylinder 2031 welded to the upper surface of the rectangular groove 2032 on the left side of the rack 203, achieving radial positioning. The fixing block 205 is installed at the lower left end of the rack 203 by the fixing screw 206 and the threaded engagement of the first threaded hole 2033, thereby restricting the axial movement of the head of the push rod 202 along the cylinder 2031, completing the reliable connection between the push rod and the rack. The incomplete gear 204 and the support shaft 308, as well as the upper support rod 301 and the support shaft 308, are connected via three evenly distributed keys on the support shaft 308. The axial positioning of the incomplete gear 204 and the upper support rod 301 is achieved through the combined action of the first splined bushing 307, the second splined bushing 309, the support shaft stop 310, and the bolts 311. The keyed connections ensure that the incomplete gear 204 and the upper support rod 301 can achieve synchronous rotational motion, transforming the linear motion of the push rod into the rotational motion of the upper support rod, thus changing the curtain support device from its folded state to its unfolded working state.

[0027] See also Figure 1 , Figure 5 As shown, when the projection screen is in the middle of its upper and lower limit positions and the screen needs to stop retracting, the hollow electromagnet 314, after being energized and magnetized, generates a large frictional force between itself and the annular iron piece 313 embedded in the tail of the lower support rod 303. This hinders the relative rotation between the upper support rod 301 and the lower support rod 303, thereby achieving the purpose of suspending the projection screen at any position. The upper support rod 301 and the hollow electromagnet 314 are tightly fitted, while the lower support rod 303 and the hollow electromagnet 314 are loosely fitted, thus allowing the upper support rod 301 and the lower support rod 303 to rotate. The upper support rod 301, the hollow electromagnet 314, and the lower support rod 303 are axially fixed through the action of the lower support rod stop 312, the washer 315, and the fixing bolt 316.

[0028] The structural features of the present invention have been described in detail above with reference to the illustrations. The present invention is not limited to the scope of implementation shown in the illustrations. Any changes made in accordance with the concept of the present invention, or equivalent embodiments modified to have equivalent changes, shall be within the protection scope of the present invention as long as they do not exceed the spirit covered by the specification and illustrations.

Claims

1. A locking projection screen support device based on a hollow electromagnet, characterized in that: It consists of a drive mechanism, a support mechanism, and a fixed module; The drive mechanism consists of a fixing bolt (201), a push rod (202), a rack (203), an incomplete gear (204), a fixing block (205), a fixing screw (206), and a first threaded hole (2033); the push rod (202) has a tail mounting hole (2021) and a head mounting hole (2022), and the push rod (202) is fixedly connected to the upper fixing plate (101) by means of the tail mounting hole (2021) and the fixing bolt (201); the head mounting hole (2022) is sleeved on the cylinder (2031), and the cylinder (2031) 1) A component welded in a rectangular groove (2032) on the left side of the rack (203); a fixing block (205) is installed on the lower left end of the rack (203) by a fixing screw (206) and a threaded engagement with the first threaded hole (2033), restricting the head of the push rod (202) from moving axially along the cylinder (2031), thereby realizing the connection between the push rod (202) and the rack (203); the rack (203) meshes with an incomplete gear (204) through a gear rack pair, converting the linear motion of the push rod (202) into the rotational motion of the incomplete gear (204); The support mechanism includes an upper support rod (301), a lower support rod (303), a bushing (305), a lower mounting block (306), a first spline bushing (307), a support shaft (308), a second spline bushing (309), a support shaft stop (310), a lower support rod stop (312), an annular iron sheet (313), and a hollow electromagnet (314); the upper support rod (301) has an upper support rod head keyway (3011) at its head, the first spline bushing (307) has a first bushing keyway (3071), and the second spline bushing (309) has a first bushing keyway (3071). The bushing (309) is provided with a second bushing keyway (3091), and the upper support rod head keyway (3011), the first bushing keyway (3071), and the second bushing keyway (3091) are all matched with the gear keyway (2041); three keys are evenly distributed along the circumference on the support shaft (308), and the first spline bushing (307), the second spline bushing (309), the incomplete gear (204), and the upper support rod (301) are all configured to cooperate with the support shaft (308) through keyways, so as to realize the connection between the support shaft (308) and the upper support rod (301). Synchronous rotation; the upper support rod (301) has an upper support rod circular groove (3012) at its tail; the lower support rod (303) has a lower support rod circular groove (3031) at its tail; the left half of the hollow electromagnet (314) is the adsorption end (3141), and the right half is the fixing end (3142). The fixing end (3142) of the hollow electromagnet (314) is installed in the upper support rod circular groove (3012) with an interference fit; the adsorption end (3141) of the hollow electromagnet (314) is installed in the lower support rod circular groove (3031) with a clearance fit. In the groove (3031); the annular iron sheet (313) is embedded in the bottom of the circular groove (3031) of the lower support rod and attracts the adsorption end (3141) of the hollow electromagnet (314); the lower support rod stop (312) and the through hole at the tail of the lower support rod (303) form a clearance fit; there is a clearance fit between the hollow electromagnet (314) and the circular groove (3031) of the lower support rod, and between the lower support rod stop (312) and the lower support rod (303), so as to realize the relative rotation between the upper support rod (301) and the lower support rod (303); The fixing module consists of the upper fixing plate (101) and the curtain traction plate (102).

2. The locking projection screen support device based on a hollow electromagnet according to claim 1, characterized in that: The push rod (202) in the drive mechanism is installed inside the rectangular ring (1011) welded to the upper fixed plate (101), and two rectangular rings (1011) are provided; the upper surface of the rack (203) is attached to the surface of the sliding groove (1014), and the limiting effect of the sliding groove (1014) ensures that the rack (203) moves linearly along the extension and retraction direction of the push rod (202) without deflection; the inside of the incomplete gear (204) is provided with a gear keyway (2041), and the gear keyway (2041) is provided with three keyways that are evenly distributed around the circumference.

3. The locking projection screen support device based on a hollow electromagnet according to claim 1, characterized in that: The support shaft (308) is installed between the first mounting hole (1012) and the second mounting hole (1013) on the left and right sides of the upper fixed plate (101) through the shaft hole. The support shaft (308) is axially positioned by the support shaft stop (310) fixed by the bolt (311). The upper support rod (301) has a second threaded hole (3013) at its tail and the lower support rod (303) has a through hole at its tail. The upper support rod (301), the hollow electromagnet (314) and the lower support rod (303) are axially fixed by the fixing action of the fixing nut (302), the fixing bolt (316), the second threaded hole (3013) and the washer (315).

4. The locking projection screen support device based on a hollow electromagnet according to claim 1, characterized in that: The head of the lower support rod (303) is connected to the lower mounting block (306) by an internal hex bolt (304) and is axially positioned by a bushing (305); the curtain traction plate (102) is fixedly connected to the lower mounting block (306) by bolts.

5. The locking projection screen support device based on a hollow electromagnet according to claim 1, characterized in that: The drive mechanism, support mechanism, and upper fixing plate (101) are all provided in twos and are symmetrically installed on both sides of the screen traction plate (102) in the fixing module. The drive mechanisms on both sides move synchronously to ensure the consistency of the movement of the support mechanisms on both sides. The upper fixing plate is installed on the lower end of the car or the outer shell of the projection screen by bolts. The screen traction plate (102) is movably installed together with the projection screen. The above structure allows the screen to be easily extended and retracted.

6. The locking projection screen support device based on a hollow electromagnet according to claim 1, characterized in that: The upper support rod (301) and the lower support rod (303) are rotatably connected, and the hollow electromagnet (314) is installed at the connection between the upper and lower support rods; the annular iron sheet (313) is installed on the bottom surface of the circular groove (3031) of the lower support rod and is positioned opposite to the adsorption end (3141); the contact surface between the annular iron sheet (313) and the adsorption end (3141) is provided with a friction-enhancing coating. After the hollow electromagnet (314) is energized and magnetized, the coating is tightly attached to the adsorption end (3141) of the hollow electromagnet (314), generating a frictional force sufficient to prevent relative rotation between the upper support rod (301) and the lower support rod (303), thereby enabling the projection screen to be suspended and stabilized at any position.

Images