A special forming die for automobile gear forgings

Abstract

The present invention belongs to the field of forging dies and provides a special forming die for automobile gear forgings, comprising a base plate, on which a plurality of elastic telescopic rods are fixedly mounted, the tops of the plurality of elastic telescopic rods being fixedly connected to the same mounting ring, on which a gear die with openings on both sides is rotatably mounted; shielding mechanisms are installed on both sides of the gear die, the shielding mechanism at the bottom is used to block the bottom of the gear die, and the shielding mechanism at the top is rotated to the side of the gear die to expose the opening at the top of the gear die. The present invention provides a reversible gear die so that the blank can be processed multiple times in the gear die, and before and after reversing, the blank can be punched while ensuring the quality of the punching. During forging, the device does not need to transfer the forgings between multiple dies, thus avoiding burns to the workers, saving the time of transferring the forgings, and improving the forging efficiency.

Description

Technical Field

[0001] The invention belongs to the field of forging dies, and in particular relates to a special forming die for automobile gear forgings. Background Art

[0002] Forgings are workpieces or blanks obtained by forging and deforming metal billets. Forging is a processing method that uses a forging machine to apply pressure to the metal billet, causing it to plastically deform, resulting in forgings with specific mechanical properties, shapes, and sizes. Forging eliminates defects such as as-cast porosity that occur during the metal smelting process, optimizes the microstructure, and, by preserving the integrity of the metal's flow lines, generally results in mechanical properties superior to those of castings made of the same material.

[0003] Gears are crucial transmission components in automobiles, widely used in heavy trucks, light trucks, cars, motorcycles, and minivans. Existing automotive gears are often forged using dies. However, during the forging process, scrap material can easily bounce around, endangering operator safety. Furthermore, the forging process requires repeated reheating, which is extremely cumbersome and inefficient.

[0004] In response to the above technical problems, the applicant has retrieved some existing technologies, such as the Chinese patent forging die, forging method and gear forging for automotive rear axle with patent publication number CN114226612B. The forging die includes a gear prototype forging die, a punching die, and a tooth prototype forging die. By using the gear prototype forging die, the punching die and the tooth prototype forging die, it can facilitate the assembly line forging operation and improve the forging efficiency of the gear.

[0005] However, the above patent solution sets three molds. Since the forgings need to be transferred among the three molds, and the forgings are kept at a high temperature after each forging, it is easy to burn the workers during the transfer process. Moreover, since each mold is concave, it is not easy to remove the forgings from the mold when transferring them, which will waste a lot of time and reduce the efficiency of gear forging. Summary of the Invention

[0006] The purpose of the present invention is to provide a special forming die for automobile gear forgings, aiming to solve the technical problems in the prior art of transferring between multiple dies, easily scalding workers, and reducing forging efficiency due to difficulty in removing forgings from the die.

[0007] The present invention is achieved by providing a special forming die for automotive gear forgings, comprising a base plate, a plurality of elastic telescopic rods fixedly mounted on the base plate, the tops of the plurality of elastic telescopic rods being fixedly connected to a common mounting ring, a gear die with openings on both sides being rotatably mounted on the mounting ring;

[0008] Shielding mechanisms are installed on both sides of the gear die. The bottom shielding mechanism is used to block the bottom of the gear die to make the bottom of the forging flat. The top shielding mechanism can be rotated to the side of the gear die to expose the opening at the top of the gear die, which is convenient for placing and extruding the billet.

[0009] A second telescopic rod and a first telescopic rod are further mounted on the bottom plate, an abutment plate is fixedly mounted on the second telescopic rod, a punching column is fixedly mounted on the first telescopic rod, and a through hole is opened on the abutment plate for the punching column to pass through;

[0010] A driving mechanism is also installed on the bottom plate, one end of which is connected to the gear mold, and the driving mechanism is used to drive the gear mold to flip.

[0011] Further technical solution: The shielding mechanism includes a rotating motor fixedly mounted on the gear mold, the output shaft of the rotating motor is fixedly connected to a baffle, the surface of the baffle is in contact with the surface of the gear mold, and a through hole adapted to the punching column is provided on the baffle.

[0012] Further technical solution: The elastic telescopic rod includes a fixed cylinder fixedly installed on the base plate, a movable rod is slidably installed on the top of the fixed cylinder, the mounting ring is fixedly installed on the top of the movable rod, and a compression spring is arranged between the movable rod and the fixed cylinder.

[0013] Further technical solution: The driving mechanism includes a driving motor fixedly mounted on the base plate, the output shaft of the driving motor is fixedly connected to a driving rod, a tensioning assembly is also mounted on the base plate, one end of the driving rod, the output end of the tensioning assembly and one end of the gear mold are all fixedly connected to sprockets, and the multiple sprockets are connected by chain transmission.

[0014] Further technical solution: The tensioning assembly includes a fixed base fixedly installed on the base plate, a tensioning block is slidably installed on the side of the fixed base, a first tension spring is connected between the tensioning block and the fixed base, a tensioning rod is rotatably installed on the tensioning block, and one of the sprockets is fixedly installed at one end of the tensioning rod.

[0015] Further technical solution: A locking mechanism is provided between the gear mold and the baffle. When the baffle blocks the opening of the gear mold, the locking mechanism is used to fix the baffle to the gear mold.

[0016] Further technical solution: the locking mechanism includes an active cavity opened on the gear mold, and a gravity slider is slidably installed inside the active cavity. A second tension spring is connected between the side of the gravity slider facing away from the axis of the gear mold and the side wall of the active cavity. Initially, the weight of the gravity slider is much greater than the elastic force of the second tension spring, and the maximum elastic force of the second tension spring is greater than the friction force between the gravity slider and the gear mold. An "L"-shaped claw is fixedly connected to the top of the gravity slider, and a first movable gap is opened on the gear mold for the claw to extend and move. An arc groove adapted to the claw is opened on the side of the baffle, and a lock groove adapted to the claw is opened on the side of the arc groove.

[0017] Further technical solution: The locking mechanism also includes a locking plate, which is slidably mounted on the gravity slider, and a sliding groove that is compatible with the locking plate is provided on the gravity slider, a slot that is compatible with the locking plate is provided on the baffle, and a locking hole is provided on the top for the locking plate to pass through.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention provides a reversible gear die, so that the blank can be processed multiple times in the gear die. Before and after reversal, the blank can be punched while ensuring the punching quality. During forging, the device does not need to transfer the forgings between multiple dies, thus avoiding burns to workers, saving time in transferring forgings, and improving forging efficiency.

[0020] 2. The present invention provides a locking mechanism to connect the baffle to one end of the gear die, thereby allowing the gear die to bear part of the pressure from the forging, reducing the force exerted by the baffle on the output shaft of the rotating motor, avoiding damage to the rotating motor due to large acting torque, and extending the service life of the rotating motor;

[0021] 3. The present invention provides a locking plate. During the flipping process of the gear mold, after the hook claw is inserted into the locking groove, the locking plate will gradually extend from the slide groove and insert into the slot on the baffle. After the gear mold is completely flipped, one end of the locking plate is completely inserted into the slot, thereby preventing the gravity slider from returning prematurely. This solves the problem that when wear occurs between the gravity slider and the gear mold, resulting in a decrease in the friction coefficient between the gravity slider and the gear mold, the friction between the gear mold and the gravity slider cannot overcome the elastic force of the second tension spring, causing the gravity slider to return prematurely, and the gravity of the blank is completely applied to the output shaft of the rotating motor, causing damage to the rotating motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall top view of the structure of the present invention.

[0023] Figure 2 It is a schematic diagram of the overall bottom-up structure of the present invention.

[0024] Figure 3 It is a schematic diagram of the cross-sectional structure of the gear mold in the present invention.

[0025] Figure 4 For the present invention Figure 3 Enlarged schematic diagram of point A in the middle.

[0026] Figure 5 For the present invention Figure 3 Enlarged schematic diagram of point B in the middle.

[0027] Figure 6 It is a bottom view structural diagram of the baffle in the present invention.

[0028] In the accompanying drawings: 1. Base plate; 2. Elastic telescopic rod; 21. Fixed cylinder; 22. Movable rod; 3. Driving mechanism; 31. Driving motor; 32. Driving rod; 33. Tensioning rod; 34. Sprocket; 35. Chain; 36. Tensioning block; 37. First tension spring; 38. Fixed seat; 4. First telescopic rod; 5. Mounting ring; 6. Gear mold; 7. Baffle; 8. Punching column; 9. Locking mechanism; 91. Second tension spring; 92. Hook; 93. First movable gap; 94. Gravity slider; 95. Locking plate; 96. Locking hole; 97. Slide groove; 98. Slot; 99. Locking groove; 910. Movable cavity; 911. Arc groove; 10. Abutment plate; 11. Rotating motor; 12. Through hole; 13. Second telescopic rod. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0030] The specific implementation of the present invention is described in detail below with reference to specific embodiments.

[0031] like Figures 1-6 The figure shows a special forming die for automotive gear forgings provided by the present invention, comprising a base plate 1, on which a plurality of elastic telescopic rods 2 are fixedly mounted. The tops of the plurality of elastic telescopic rods 2 are fixedly connected to a common mounting ring 5, on which a gear die 6 with openings on both sides is rotatably mounted.

[0032] Shielding mechanisms are installed on both sides of the gear die 6. The two shielding mechanisms are respectively marked as shielding mechanism No. 1 and shielding mechanism No. 2. The shielding mechanism No. 2 is used to block the bottom of the gear die 6 to make the bottom of the forging flat. The shielding mechanism No. 1 can be rotated to the side of the gear die 6 to expose the opening at the top of the gear die 6, which is convenient for placing and extruding the billet.

[0033] The bottom plate 1 is further provided with a second telescopic rod 13 and a first telescopic rod 4. The second telescopic rod 13 is fixedly provided with an abutment plate 10. The first telescopic rod 4 is fixedly provided with a punching column 8. The abutment plate 10 is provided with a through hole for the punching column 8 to pass through.

[0034] A driving mechanism 3 is further installed on the bottom plate 1 , one end of the driving mechanism 3 is connected to the gear mold 6 , and the driving mechanism 3 is used to drive the gear mold 6 to flip.

[0035] When in use, the second telescopic rod 13 drives the abutment plate 10 to rise, so that the abutment plate 10 abuts against the bottom of the No. 2 shielding mechanism, and then the first telescopic rod 4 drives the punching column 8 to rise, so that the punching column 8 passes through the abutment plate 10 and is level with the No. 2 shielding mechanism, and then the staff puts the high-temperature blank into the gear mold 6 and uses the forging press to extrude the blank, and then the second telescopic rod 13 drives the abutment plate 10 to descend to a certain height, and the descending height is less than the thickness of the gear mold 6, and then the forging press extrude the blank again, because there is no abutment plate 10 to block it, the blank will fall synchronously with the gear mold 6 until the No. 2 shielding mechanism is blocked by the abutment plate 10, and because the height of the punching column 8 remains unchanged, when the blank falls, the punching column 8 will penetrate into the interior of the blank to punch the blank;

[0036] Then, the second telescopic rod 13 drives the abutment plate 10 to descend, the first telescopic rod 4 drives the punching column 8 to descend, and the No. 1 shielding mechanism blocks the top opening of the gear mold 6. Then, the driving mechanism 3 drives the gear mold 6 to rotate 180°, and then the No. 2 shielding mechanism rotated above the gear mold 6 is opened to expose the opening of the gear mold 6. Then, the first telescopic rod 4 drives the punching column 8 to rise, so that the punching column 8 abuts against the bottom of the blank. Then, the second telescopic rod 13 drives the abutment plate 10 to rise, so that the abutment plate 10 rises to the position of the last movement. That is, the distance between the top of the abutment plate 10 and the bottom of the blank is made smaller than the thickness of the gear die 6, and the blank is extruded again using a forging press. Then, the punching column 8 punches the blank from two directions, and the hole can be penetrated. Finally, the second telescopic rod 13 drives the abutment plate 10 to descend, so that the distance between the top of the abutment plate 10 and the blank is equal to the thickness of the gear die 6. Then, the blank is extruded once more by the forging press, so that the blank can be perfectly formed in the gear die 6. At the same time, the punching column 8 will also penetrate the blank completely, so that the gear forging retains a perfect shaft hole.

[0037] The device eliminates the need to transfer forgings between multiple molds, thus avoiding burns to workers, saving time in transferring forgings, and improving forging efficiency.

[0038] The present invention provides a special forming die for automobile gear forgings. In this embodiment, the shielding mechanism includes a rotating motor 11 fixedly mounted on the gear die 6, the output shaft of the rotating motor 11 is fixedly connected to a baffle 7, the surface of the baffle 7 is in contact with the surface of the gear die 6, and the baffle 7 is provided with a through hole 12 adapted to the punching column 8.

[0039] Specifically, the rotating motor 11 is connected to an eccentric position of the baffle 7 . When the baffle 7 blocks the gear mold 6 , the axis of the baffle 7 and the axis of the gear mold 6 coincide with each other.

[0040] During the flipping process of the gear die 6, the two baffles 7 seal the two sides of the gear die 6, thereby preventing the blank in the gear die 6 from falling. After the flipping is completed, the baffle 7 on the top of the gear die 6 is rotated to the side of the gear die 6 to expose the blank so that the forging machine can extrude it.

[0041] The present invention provides a special forming mold for automobile gear forgings. In this embodiment, the elastic telescopic rod 2 includes a fixed cylinder 21 fixedly installed on the base plate 1, and a movable rod 22 is slidably installed on the top of the fixed cylinder 21. The mounting ring 5 is fixedly installed on the top of the movable rod 22, and a compression spring is arranged between the movable rod 22 and the fixed cylinder 21.

[0042] Specifically, initially, the elastic force of the compression spring is made much greater than the gravity of the blank, so that when the blank is turned over, the mounting ring 5 can be prevented from shaking up and down, thereby avoiding affecting the movement of the driving mechanism 3.

[0043] The present invention provides a special forming mold for automobile gear forgings. In this embodiment, the driving mechanism 3 includes a driving motor 31 fixedly mounted on a base plate 1, and the output shaft of the driving motor 31 is fixedly connected to a driving rod 32. A tensioning assembly is also mounted on the base plate 1, and one end of the driving rod 32, the output end of the tensioning assembly, and one end of the gear mold 6 are all fixedly connected to a sprocket 34, and the multiple sprockets 34 are connected by a chain 35 for transmission.

[0044] Specifically, the driving motor 31 can drive the sprocket 34 to rotate through the driving rod 32, and the sprocket 34 can drive the gear mold 6 to rotate through the chain 35, so that the gear mold 6 can be flipped. When the gear mold 6 is squeezed and lowered, the tensioning assembly can tension the chain 35 to prevent the chain 35 from falling off the sprocket 34, thereby keeping the entire working process smooth and reducing the maintenance of the device.

[0045] The present invention provides a special forming mold for automobile gear forgings. In this embodiment, the tensioning assembly includes a fixed seat 38 fixedly mounted on the base plate 1, and a tensioning block 36 is slidably mounted on the side of the fixed seat 38. A first tension spring 37 is connected between the tensioning block 36 and the fixed seat 38. A tensioning rod 33 is rotatably mounted on the tensioning block 36, and one of the sprockets 34 is fixedly mounted on one end of the tensioning rod 33.

[0046] Initially, the first tension spring 37 remains in a tensioned state. When the gear mold 6 descends, the sprocket 34 on the gear mold 6 relaxes the tension on the chain 35, and the first tension spring 37 pulls the tensioning block 36 and the tensioning rod 33 away from the drive motor 31, keeping the chain 35 in a tensioned state.

[0047] The present invention provides a special forming die for automobile gear forgings. Since the blank is heavy and the output shaft of the rotating motor 11 is located at the edge position far away from the axis of the baffle 7, after the gear die 6 carrying the blank is flipped, the center of gravity of the force exerted by the blank on the baffle 7 is at the axis position of the baffle 7, so that the torque of the baffle 7 on the output shaft of the rotating motor 11 is large, which can easily damage the rotating motor 11. Therefore, in this embodiment, a locking mechanism 9 is further provided between the gear die 6 and the baffle 7. When the baffle 7 blocks the opening of the gear die 6, the locking mechanism 9 is used to fix the baffle 7 to the gear die 6, so that the gear die 6 bears part of the force, avoiding damage to the rotating motor 11 due to the large torque.

[0048] The present invention provides a special forming die for automotive gear forgings. In this embodiment, the locking mechanism 9 includes a movable cavity 910 opened on the gear die 6. A gravity slider 94 is slidably installed inside the movable cavity 910. A second tension spring 91 is connected between the side of the gravity slider 94 facing away from the axis of the gear die 6 and the side wall of the movable cavity 910. Initially, the weight of the gravity slider 94 is much greater than the elastic force of the second tension spring 91. For example, the weight of the gravity slider 94 is twice or three times the maximum elastic force of the second tension spring 91, and the second The maximum elastic force of the tension spring 91 is greater than the friction between the gravity slider 94 and the gear mold 6, so that the second tension spring 91 can pull the gravity slider 94 back. The top of the gravity slider 94 is fixedly connected with an "L"-shaped hook 92. The gear mold 6 is provided with a first movable gap 93 for the hook 92 to extend and move. The side of the baffle 7 is provided with an arc groove 911 that is compatible with the hook 92, so as to prevent the hook 92 from affecting the movement of the baffle 7. The side of the arc groove 911 is provided with a locking groove 99 that is compatible with the hook 92.

[0049] Specifically, during the rotation of the baffle 7, the hook 92 will pass through the arc groove 911. When the baffle 7 blocks the gear mold 6, the axis of the baffle 7 and the axis of the gear mold 6 coincide. At this time, the locking groove 99 is on the side of the hook 92. When the driving mechanism 3 drives the gear mold 6 to flip, under the action of gravity, the gravity slider 94 overcomes the pulling force of the second tension spring 91 and slides toward the center of the gear mold 6. The gravity slider 94 drives the hook 92 to insert into the locking groove 99. Figure 5 As shown, one end of the baffle 7 is connected to the gear mold 6 through the hook 92 and the gravity slider 94, so that the gear mold 6 shares the pressure on the baffle 7, reducing the force of the baffle 7 on the rotating motor 11, avoiding damage to the rotating motor 11 caused by the baffle 7, and extending the service life of the rotating motor 11;

[0050] After the gear mold 6 is turned over, the blank is pressed against the baffle 7, causing the baffle 7 to pull the gravity slider 94 through the claw 92, increasing the pressure between the gravity slider 94 and the gear mold 6, thereby increasing the friction between the gear mold 6 and the gravity slider 94. This friction overcomes the elastic force of the second tension spring 91, so that the gravity slider 94 and the claw 92 remain in place.

[0051] When the gear mold 6 is flipped over again, the gravity slider 94 at the bottom of the gear mold 6 will be flipped to its top, and the gravity slider 94 is only subjected to pressure from the baffle 7. Therefore, the second tension spring 91 can pull the gravity slider 94 back to the initial position, releasing the connection between the hook 92 and the baffle 7. At this time, the baffle 7 can be driven to rotate by the rotating motor 11 to open the opening on the gear mold 6 and expose the blank.

[0052] The present invention provides a special forming mold for automobile gear forgings. After long-term use, wear will occur between the gravity slider 94 and the gear mold 6, resulting in a decrease in the friction coefficient between the gravity slider 94 and the gear mold 6. When the blank is pressed on the baffle 7, the friction force between the gear mold 6 and the gravity slider 94 cannot overcome the elastic force of the second tension spring 91, causing the gravity slider 94 to return prematurely, causing the gravity of the blank to act completely on the output shaft of the rotating motor 11, which will still cause damage to the rotating motor 11. Therefore, in this embodiment, the locking mechanism 9 also includes a locking plate 95, which is slidably mounted on the gravity slider 94, and the gravity slider 94 is provided with a slide groove 97 adapted to the locking plate 95, the baffle 7 is provided with a slot 98 adapted to the locking plate 95, and the 6 is provided with a locking hole 96 for the locking plate 95 to pass through.

[0053] Specifically, when the locking mechanism 9 is at the top of the gear mold 6, the locking plate 95 is retracted into the chute 97 under the action of gravity. During the turning process of the gear mold 6, the locking plate 95 gradually extends from the chute 97 and is inserted into the slot 98 on the baffle 7. After the gear mold 6 is completely turned over, one end of the locking plate 95 is completely inserted into the slot 98, thereby preventing the gravity slider 94 from returning prematurely.

[0054] When the gear mold 6 is turned over again, the locking plate 95 will retract into the sliding groove 97 on the gravity slider 94, and then the second tension spring 91 can pull the gravity slider 94 back to its original position. Figure 4 shown.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0056] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A special forming die for automobile gear forgings, comprising a base plate, characterized in that: A plurality of elastic telescopic rods are fixedly mounted on the bottom plate, and the tops of the plurality of elastic telescopic rods are fixedly connected to a same mounting ring, on which a gear mold with openings on both sides is rotatably mounted; Shielding mechanisms are installed on both sides of the gear mold. The bottom shielding mechanism is used to block the bottom of the gear mold, and the top shielding mechanism is rotated to the side of the gear mold to expose the opening at the top of the gear mold. A second telescopic rod and a first telescopic rod are further mounted on the bottom plate, an abutment plate is fixedly mounted on the second telescopic rod, a punching column is fixedly mounted on the first telescopic rod, and a through hole is opened on the abutment plate for the punching column to pass through; A driving mechanism is also installed on the bottom plate, one end of which is connected to the gear mold, and the driving mechanism is used to drive the gear mold to flip; The driving mechanism includes a driving motor fixedly mounted on a base plate, the output shaft of the driving motor is fixedly connected to a driving rod, a tensioning assembly is also mounted on the base plate, one end of the driving rod, the output end of the tensioning assembly and one end of the gear mold are all fixedly connected to sprockets, and the plurality of sprockets are connected by a chain transmission; The tensioning assembly includes a fixed base fixedly mounted on the base plate, a tensioning block is slidably mounted on the side of the fixed base, a first tension spring is connected between the tensioning block and the fixed base, a tensioning rod is rotatably mounted on the tensioning block, and one of the sprockets is fixedly mounted on one end of the tensioning rod.

2. The special forming die for automobile gear forgings according to claim 1, characterized in that: The shielding mechanism includes a rotating motor fixedly mounted on the gear mold, the output shaft of the rotating motor is fixedly connected to a baffle, the surface of the baffle contacts the surface of the gear mold, and a through hole adapted to the punching column is opened on the baffle.

3. The special forming die for automobile gear forgings according to claim 1, characterized in that: The elastic telescopic rod includes a fixed cylinder fixedly mounted on the bottom plate, a movable rod is slidably mounted on the top of the fixed cylinder, the mounting ring is fixedly mounted on the top of the movable rod, and a compression spring is provided between the movable rod and the fixed cylinder.

4. The special forming die for automobile gear forgings according to claim 2, characterized in that: A locking mechanism is further provided between the gear mold and the baffle. When the baffle blocks the opening of the gear mold, the locking mechanism is used to fix the baffle to the gear mold.

5. The special forming die for automobile gear forgings according to claim 4, characterized in that: The locking mechanism includes an active cavity opened on the gear mold, a gravity slider is slidably installed inside the active cavity, a second tension spring is connected between the side of the gravity slider facing away from the axis of the gear mold and the side wall of the active cavity, the weight of the gravity slider is greater than the maximum elastic force of the second tension spring, and the initial elastic force of the second tension spring is greater than the friction force between the gravity slider and the gear mold, an "L"-shaped claw is fixedly connected to the top of the gravity slider, a first movable gap is opened on the gear mold for the claw to extend and move, an arc groove is opened on the side of the baffle to match the claw, and a lock groove is opened on the side of the arc groove to match the claw.

6. The special forming die for automobile gear forgings according to claim 5, characterized in that: The locking mechanism also includes a locking plate, which is slidably mounted on the gravity slider. A sliding groove adapted to the locking plate is provided on the gravity slider, and a slot adapted to the locking plate is provided on the baffle.

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