Grain crushing device with inter-roller gap synchronous adjustment and position double locking

Abstract

This invention discloses a grain crushing device with synchronous adjustment of the gap between the two rollers and dual locking of the position, belonging to the field of agricultural machinery technology. The device includes a main frame, a floating crushing roller, a fixed crushing roller, a spiral push shaft, sprockets, a chain, and a gap adjustment tool. The fixed crushing roller is fixed to the main frame, while the floating crushing roller is movably mounted on the main frame. Two spiral push shafts are respectively located on the left and right sides of the main frame, threaded into the frame, with their front ends abutting against the floating crushing roller. Two sprockets are respectively fixed to the ends of the two spiral push shafts, and the chain connects the two sprockets to achieve synchronous transmission. During gap adjustment, the spiral push shaft is rotated using the gap adjustment tool. Under the synchronous transmission of the sprockets and chain, the spiral push shafts on both sides synchronously push the floating crushing roller to move, ensuring consistent gap on both sides of the rollers. This invention also features a dual locking mechanism to ensure a minimum safe gap. This device has advantages such as convenient synchronous gap adjustment, good consistency, reliable locking, and high frame strength.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery technology, specifically to a grain crushing device for a self-propelled forage harvester with synchronous adjustment of the roller gap and dual locking of the position. Background Technology

[0002] The grain crushing device is an important component of the self-propelled forage harvester. During the harvesting process, by crushing the corn kernels, the nutrients inside the corn kernels can be exposed, which is conducive to the storage and fermentation of silage, improves the nutritional value of forage, and enhances the quality of livestock products.

[0003] Currently available grain crushing devices suffer from problems such as low overall crushing rate, poor consistency in the gap between the left and right rollers, and difficulty in adjusting the roller gap. Specifically, the gap adjustment of existing grain crushing devices is mostly done by adjusting the left and right sides separately. After adjustment, the gap values ​​on both sides need to be measured with feeler gauges and compared repeatedly to ensure consistency. This operation is cumbersome and the accuracy is difficult to guarantee.

[0004] For example, Chinese utility model patent CN212993115U discloses a gap adjustment device for the grain crushing roller of a forage harvester. This device includes a support, a fixed crushing roller, a floating crushing roller, a swinging device, a swinging drive device, a gap detection device, and a control device. A displacement sensor detects the gap value and feeds it back to the controller. A stepper motor drives an adjusting screw to swing a cam, achieving automatic gap adjustment. However, this technical solution has the following shortcomings: First, it uses an electrically controlled or electric actuator, which has a complex structure and high manufacturing cost. Furthermore, electrical components such as sensors and motors are prone to failure in field operation environments with vibration, dust, and high humidity, making reliability difficult to guarantee. Second, it can only achieve single-point gap adjustment and cannot guarantee the consistency of the gap between the left and right sides of the crushing roller; manual verification is still required after adjustment.

[0005] To address the problems of low crushing rate, inconvenient gap adjustment, poor consistency of left and right gaps, and insufficient locking reliability in the existing technologies, this invention provides a grain crushing device with synchronous adjustment of roller gap and dual locking of position. By combining a mechanical synchronous adjustment mechanism with a dual locking structure, it achieves the technical effects of high-efficiency crushing, rapid adjustment, left and right synchronization, and dual locking. Summary of the Invention

[0006] The technical problem to be solved by this invention is to provide a grain crushing device for a forage harvester that features high grain crushing rate, easy disassembly and maintenance, convenient and rapid synchronous adjustment of the grain crushing gap, and reliable guarantee of minimum safe gap. Technical Solution To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A grain crushing device with synchronous adjustment of roller gap and dual locking of position includes a top cover (1), a main frame (2), a floating crushing roller (3), a fixed crushing roller (4), a safety connecting bridge (5), a spiral push shaft (6), a locking mechanism (7), a sprocket (8), a chain (9), a chain tensioning mechanism (10), a gap adjustment tool (11), a locking seat (12), and a push-pull groove rail (13).

[0007] The main frame (2) has a bearing seat mounting surface machined on its bottom surface. The fixed crushing roller (4) is assembled to the bottom surface of the main frame (2) by a positioning pin. A floating slide is provided between the floating crushing roller (3) and the bottom surface of the main frame (2). The floating crushing roller (3) floats back and forth by the counter-rotation of the spiral push shaft (6) and the pressure spring (19). The spiral push shaft (6) is threadedly engaged with the main frame (2). The sprocket (8) is fixed to the end of the spiral push shaft (6). The left and right sprockets (8) are connected by a chain (9) to achieve synchronous transmission. The safety connecting bridge (5) is connected between the upright plate of the main frame (2) and the bearing seat of the fixed crushing roller (4).

[0008] To achieve reliable double locking, the device is equipped with a double locking mechanism. The double locking mechanism includes a first locking unit for directly locking the helical push shaft (6) and a second locking unit for locking the sprocket (8) or the chain (9).

[0009] As a specific implementation of the first locking unit, the locking mechanism (7) is installed on the top cover (1) and cooperates with the spiral push shaft (6) to selectively clamp and lock the spiral push shaft (6). As a specific embodiment of the second locking unit, a locking seat (12) is disposed on the top cover (1). The locking seat (12) has a U-shaped structure and is used to accommodate the tail of the gap adjustment tool (11). The end of the gap adjustment tool (11) is connected to the end face of the spiral push shaft (6) to drive the spiral push shaft (6) to rotate; its tail can be inserted into the locking seat (12) and fixedly connected to the locking seat (12) by a detachable locking pin or cylindrical pin (20). When the gap adjustment tool (11) is fixed on the locking seat (12), the gap adjustment tool (11) restricts the rotation of the spiral push shaft (6) and the sprocket (8), thereby achieving the locking of the sprocket (8) and the chain (9).

[0010] The push-pull recessed rail (13) is located at the bottom of the main frame (2) and is used to slide with the external guide rail.

[0011] When adjusting the gap, the gap adjustment tool (11) is removed from the locking seat (12). The gap adjustment tool (11) is used to rotate the sprocket (8), which drives the spiral push shaft (6) to rotate synchronously. The spiral push shafts (6) on both sides complete the spiral feed and synchronously push the floating crushing roller (3) to move back and forth, ensuring that the gap between the left and right sides of the roller is consistent, without the need for feeler gauge measurement. After the adjustment is completed, the spiral push shaft (6) is locked first through the first locking unit (locking mechanism 7). Then, the tail of the gap adjustment tool (11) is inserted into the locking seat (12) and fixed with a cylindrical pin (20). The second locking unit locks the sprocket (8) and the chain (9), thus forming a double locking protection.

[0012] The chain tensioning mechanism (10) is connected to the chain (9) and is used to adjust the tension of the chain (9). The push-pull concave rail (13) is a U-shaped rail structure, used to cooperate with the convex rail on the whole machine of the forage harvester to achieve rapid push-pull assembly. Compared with the prior art, the present invention has the following beneficial effects: (1) A chain-type roller gap synchronous adjustment mechanism was designed, which adjusts the gap on both sides of the roller synchronously, avoiding the cumbersome operation of adjusting one side separately and requiring feeler gauge measurement. The adjustment efficiency is high and the consistency is good.

[0013] (2) A dual locking mechanism was designed. The first locking unit directly locks the actuator (screw push shaft), while the second locking unit locks the transmission element (sprocket / chain). The two locking layers are independent of each other and work together, which greatly improves the reliability of locking, effectively prevents gap drift under vibration conditions, and ensures the stability of long-term operation.

[0014] (3) Compared with the hydraulic synchronous cylinder type roller gap synchronous adjustment mechanism, the maintenance cost is lower and the reliability is better, which can avoid the roller gap returning to zero due to faults such as oil seepage and oil leakage.

[0015] (4) A safety connecting bridge was designed to effectively prevent frame deformation and damage caused by the increase of the pressure spring compression force. At the same time, it integrates hoisting function to facilitate transportation.

[0016] (5) A push-pull recessed rail was designed, which allows for quick pushing and pulling during maintenance and assembly, improving maintenance convenience. (See attached diagram for details.) Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the overall structure of the present invention (b); Figure 3 This is a schematic diagram of the gap adjustment mechanism of the grain crushing device; Figure 4 A schematic diagram of the roller gap locking mechanism is shown in Figure a. Figure 5 This is a schematic diagram (b) of the roller gap locking mechanism; Figure 6 This is a schematic diagram of the chain tensioning mechanism; Figure 7 This is a structural schematic diagram of the safety connection bridge; In the picture: 1-Top cover; 2-Main frame; 3-Floating crushing roller; 4-Fixed crushing roller; 5-Safety connecting bridge; 6-Spiral push shaft; 7-Locking mechanism; 8-Sprocket; 9-Chain; 10-Chain tensioning mechanism; 11-Gap adjustment tool; 12-Locking seat; 13-Push-pull recessed rail; 14-Tensioning plate A; 15-Tensioning plate B; 16-Adjusting bolt; 17-Cam locking pin; 18-Clamping mechanism; 19-Pressure spring; 20-Cylindrical pin. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0018] I. Overall Structure of the Device like Figure 1 As shown, the grain crushing device of the present invention with synchronous adjustment of roller gap and dual locking of position includes: top cover (1), main frame (2), floating crushing roller (3), fixed crushing roller (4), safety connecting bridge (5), spiral push shaft (6), locking mechanism (7), sprocket (8), chain (9), chain tensioning mechanism (10), gap adjustment tool (11), locking seat (12) and grain crushing device push-pull concave rail (13).

[0019] A bearing seat mounting surface is precision machined on the upper bottom surface of the main frame (2), and the fixed crushing roller (4) is assembled on the upper bottom surface of the main frame (2) by means of a positioning pin. A floating slide is added between the floating crushing roller (3) and the upper bottom surface of the main frame (2), and the floating crushing roller (3) floats back and forth by means of the opposing of the spiral push shaft (6) and the pressure spring (19). The spiral push shaft (6) and the main frame (2) are threaded together, and the sprocket (8) is fixed to the end of the spiral push shaft (6) by means of the shaft shoulder and the spring retaining ring. Through the connection of the chain (9), the synchronous transmission of the left and right sprockets (8) can be realized. When the sprocket (8) is rotated, the spiral push shaft (6) will rotate synchronously, and at the same time, it will push the mounting bearing seat of the floating crushing roller (3) in contact with its end to move along the floating slide, thereby realizing the gap adjustment.

[0020] like Figure 7As shown, the safety connecting bridge (5) is bolted to the upright plate of the main frame (2) and the bearing seat of the fixed crushing roller (4). In the prior art, when the compression force of the floating roller backup spring is increased to meet the large feed demand, it is easy to cause deformation and premature damage to the upright plate at the contact point between the main frame (2) and the backup spring. The present invention adds a safety connecting bridge (5) between the upright plate of the main frame (2) and the bearing seat of the fixed crushing roller (4), and uses a rigid connection between the front and rear. When the backup spring applies pressure, the safety connecting bridge (5) bears tensile stress, which counteracts the outward deformation tendency of the frame side plate and effectively solves the above problems. At the same time, a 16mm diameter circular hole is machined above the safety connecting bridge (5) as a lifting hole for the entire device, which facilitates the transportation and installation of the device.

[0021] II. Gap Synchronous Adjustment Mechanism like Figure 1 and Figure 2 As shown, the gap adjustment mechanism of the present invention includes a spiral push shaft (6), a locking mechanism (7), a sprocket (8), a chain (9), and a gap adjustment tool (11). An external thread is machined on the spiral push shaft (6), and an internal thread hole is machined on the main frame (2) at a position corresponding to the spiral push shaft (6). The floating crushing roller (3) is moved by the spiral feed of the two spiral push shafts (6). The end faces of the spiral push shafts (6) on the left and right sides of the device are hexagonal shafts, and the center of the sprocket (8) is an internal hexagonal hole. The sprocket (8) is assembled on the end face of the spiral push shaft (6) and axially fixed with a spring retainer. The sprockets (8) on the left and right sides are then synchronously connected by the chain (9). The end of the gap adjustment tool (11) is provided with an internal hexagonal hole, which can be sleeved and fixed to the hexagonal shaft at the end of the spiral push shaft (6) through the internal hexagonal hole.

[0022] When it is necessary to adjust the gap of the grain crushing device, remove the gap adjustment tool (11) from the locking seat (12). When the hexagonal shaft at the end of the spiral push shaft (6) on one side is rotated by the gap adjustment tool (11), the spiral push shaft (6) drives the sprocket (8) on the same side to rotate. Due to the synchronous transmission of the chain (9), it will drive the sprocket (8) on the other side to rotate, thereby synchronously driving the spiral push shaft (6) on the other side to rotate. Since the main frame (2) that cooperates with the spiral push shaft (6) has a threaded structure, under the drive of the sprocket (8) and the chain (9), the spiral push shafts (6) on both sides complete the spiral feeding action, which can synchronously drive the floating crushing roller (3) to adjust its front and rear positions, and ensure the consistency of the gap between the left and right sides of the roller, without the need for feeler gauge measurement.

[0023] Most grain crushing devices have a factory clearance of 2.5mm to 3mm, but the required roller clearance varies under different operating conditions, necessitating frequent adjustments. When the moisture content of silage corn is high and the kernels are tender, the crushing difficulty increases, and the roller clearance needs to be reduced to 1.5mm to 2mm. When the yield per acre is high and the feed rate is large, the roller clearance needs to be adjusted to 3mm to 4mm to prevent material blockage. This adjustment process must be carried out with the machine completely stopped and the engine off. Traditional grain crushing devices that adjust the clearance separately on the left and right sides require the drive belt to be manually removed and pushed or pulled out of the assembly position for easy measurement of the clearance with a feeler gauge. However, the high differential speed grain crushing device with synchronous roller clearance adjustment of this invention allows for one-step adjustment without removing the drive belt or using the push-pull device.

[0024] III. Double locking mechanism for roller gap One of the core improvements of this invention is the dual locking mechanism, which includes a first locking mechanism and a second locking mechanism.

[0025] (a) First locking mechanism like Figure 3 and Figure 4 As shown, the locking mechanism (7) is installed on the top cover (1) as the first locking mechanism and is used to directly lock the spiral push shaft (6). The locking mechanism (7) includes a clamping mechanism (18) and a cam locking pin (17). The clamping mechanism includes upper and lower floating clamping plates with a gap between them. An inner hole for accommodating the spiral push shaft (6) is provided at the middle position of the floating clamping plate. The end of the cam locking pin (17) is a rotatable cam mechanism, the middle part is a through hole through which a cylinder passes through the upper floating clamping plate, and the bottom is a threaded rod, which is fixedly connected to the threaded hole of the lower floating clamping plate.

[0026] In the unlocked state, the inner hole and the spiral push shaft (6) are in clearance fit. When locking is required, the rotating cam locking pin (17) is rotated 90°. Under the lifting action of the cam surface and the bottom threaded rod, the two floating clamping plates move closer to each other, and the inner hole undergoes elastic deformation, thereby generating a clamping force to hold and fix the spiral push shaft (6), thus achieving the first locking of the actuator.

[0027] (ii) Second locking mechanism like Figure 1 and Figure 5 As shown, the locking seat (12) is a second locking mechanism and is set on the top cover (1). The end of the gap adjustment tool (11) is connected to the hexagonal shaft at the end of the spiral push shaft (6) by means of the hexagonal hole, and its tail can be inserted into the U-shaped locking seat (12).

[0028] After the gap adjustment is completed, insert the tail of the gap adjustment tool (11) into the locking seat (12) and fix it with the cylindrical pin (20). At this time, since the gap adjustment tool (11) cannot rotate, the spiral push shaft (6) connected to its profile and the sprocket (8) fixed on the spiral push shaft (6) cannot rotate, thereby locking the entire transmission chain and realizing the second locking of the transmission components. At the same time, this locking method also indirectly locks the sprocket (8) and spiral push shaft (6) on the other side.

[0029] (iii) Coordination of dual locking After the gap adjustment is completed, the operator first locks the first locking mechanisms (7) on both sides to clamp the spiral push shaft (6). Then, the gap adjustment tool (11) is placed on the locking seat (12) and the cylindrical pin (20) is inserted to achieve the second locking. The two locking layers are independent of each other and work together. Even if the first locking mechanism loosens slightly under strong vibration, the second locking mechanism can still maintain the stability of the breaking gap by locking the transmission chain, thus achieving a reliability far exceeding that of a single locking.

[0030] IV. Chain rapid tensioning mechanism like Figure 6 As shown, the present invention designs a chain tensioning mechanism (10), with both ends of the chain (9) connected to tensioning plate A (14) and tensioning plate B (15) respectively. One end of the adjusting bolt (16) abuts or connects to tensioning plate A (14). By turning the adjusting bolt (16), tensioning plate A (14) can be pushed up and moved towards tensioning plate B (15), thereby tightening the chain (9). This mechanism can quickly tension the chain (9), saving the need for a tensioning wheel, and the chain (9) can still be quickly tensioned after being stretched for a long time.

[0031] V. Operation Procedure of the Device Step 1: Gap Adjustment Preparation During corn silage harvesting, adjustments to the grain crushing gap are necessary when the moisture content of the forage changes or the yield per acre fluctuates. Before making any adjustments, the harvester must be completely stopped and the engine shut off to ensure operational safety.

[0032] Step 2: Unlock Rotate the cam locking pin (17) of the locking mechanism (7) on the top cover (1) by 90° to release the locking mechanism (7) from locking the spiral push shaft (6). At the same time, pull out the cylindrical pin on the locking seat (12), remove the clearance adjustment tool (11) from the locking seat (12), and release the lock on the sprocket (8) and chain (9).

[0033] Step 3: Connecting Adjustment Tools Align the inner hexagonal hole at the end of the gap adjustment tool (11) with the hexagonal shaft structure at the end of the spiral push shaft (6) and insert it to ensure that the surface fits properly.

[0034] Step 4: Adjust the gap between the rollers According to the working conditions, rotate the gap adjustment tool (11) clockwise or counterclockwise. Due to the synchronous transmission of the sprocket (8) and the chain (9), the spiral push shafts (6) on the left and right sides rotate synchronously. The spiral push shaft (6) is threadedly fitted with the main frame (2). When the spiral push shaft (6) rotates, it generates a feed motion along the thread axis. Under the combined action of the thrust of the spiral push shaft (6) and the reverse thrust of the pressure spring (19), the floating crushing roller (3) can be pushed to move back and forth. Due to the synchronous transmission of the chain (9), the spiral push shafts (6) on the left and right sides always maintain synchronous rotation. Therefore, the movement of the floating crushing roller (3) on the left and right sides is completely consistent, ensuring the consistency of the gap between the floating crushing roller (3) and the fixed crushing roller (4). During the adjustment process, there is no need to use a feeler gauge to measure the left and right sides separately. In this embodiment, the pitch of the spiral push shaft (6) is 1mm. For each synchronous rotation, the crushing gap can be increased or decreased by 1mm. The operator can achieve precise adjustment of the roller gap by controlling the rotation angle.

[0035] Step 5: Lock the mechanism. After the gap adjustment is completed, press the cam locking pin (17) on the left and right locking mechanisms (7). After the locking pin is pressed, the cam surface presses the upper and lower surfaces of the clamping mechanism to produce elastic deformation, thereby clamping the spiral push shaft (6) and preventing it from rotating unexpectedly under vibration conditions.

[0036] Step 6: Double Locking Place the gap adjustment tool (11) back into the fixed position on the locking seat (12), and insert the cylindrical pin (20) into the locking seat (12) to lock the sprocket (8) and the chain (9) to form a double locking protection. At this time, the minimum safe gap is 1mm to ensure that the rollers will not collide.

[0037] Step 7: Initiate the inspection Start the harvester, check the crushing effect, and continue operation after confirming that everything is in order.

[0038] Step 8: Repair and Disassembly When the grain crushing device needs maintenance, first remove the drive belt, then loosen the bolts connecting the grain crushing device to the main frame. Pull the entire grain crushing device outward along the push-pull concave rail (13). The push-pull concave rail (13) cooperates with the convex rail on the whole machine. The rail has a U-shaped structure. Through the limiting and guiding effect of the rail, rapid pushing and pulling can be achieved. Perform maintenance work on the external workbench. After maintenance is completed, push it back to its original position along the push-pull concave rail (13) and reconnect the bolts and transmission components.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A grain crushing device with synchronous adjustment of roller gap and dual position locking, characterized in that, include: Mainframe (2); The fixed crushing roller (4) is fixedly installed on the main frame (2); The floating crushing roller (3) is movably installed on the main frame (2), and is arranged parallel to the fixed crushing roller (4) with a grain crushing gap between them; There are two spiral push shafts (6), which are respectively set on the left and right sides of the main frame (2). Each spiral push shaft (6) is threadedly engaged with the main frame (2), and its front end abuts against the floating crushing roller (3) to push the floating crushing roller (3) to move. There are two sprockets (8), which are fixedly installed at the ends of the two spiral push shafts (6); A chain (9) connects the two sprockets (8) to achieve synchronous rotation of the two helical push shafts (6); A gap adjustment tool (11) is detachably connected to the end of the spiral push shaft (6) for driving the spiral push shaft (6) to rotate; And a dual locking mechanism, the dual locking mechanism comprising a first locking unit for directly locking the helical push shaft (6) and a second locking unit for locking the sprocket (8) or the chain (9).

2. The grain crushing device with synchronous adjustment of roller gap and dual position locking according to claim 1, characterized in that: A floating slide is provided between the floating crushing roller (3) and the main frame (2). The floating crushing roller (3) floats back and forth by means of the opposing forces of the spiral push shaft (6) and the pressure spring (19).

3. The grain crushing device with synchronous adjustment of roller gap and dual position locking according to claim 1, characterized in that: The end of the spiral push shaft (6) is an external hexagonal structure, and the end of the gap adjustment tool (11) is an internal hexagonal structure. The two are connected by a surface fit. The center of the sprocket (8) is an internal hexagonal structure and is assembled on the external hexagonal structure at the end of the spiral push shaft (6).

4. The grain crushing device with synchronous adjustment of roller gap and dual position locking according to claim 1, characterized in that: The first locking unit includes a locking mechanism (7) installed on the top cover (1). The cam locking pin (17) of the locking mechanism (7) is a cam structure with a rotation angle of 90°. When pressed, the cam surface presses against the clamping mechanism (18) to generate deformation, thereby clamping the spiral push shaft (6).

5. The grain crushing device with synchronous adjustment of roller gap and dual position locking according to claim 4, characterized in that: The clamping mechanism includes upper and lower floating clamping plates with a gap between them. The middle part of the floating clamping plates is provided with an inner hole for accommodating the spiral push shaft (6). The bottom of the cam locking pin (17) is a threaded rod, which is fixedly connected to the threaded hole of the lower floating clamping plate. In the locked state, the cam locking pin (17) rotates and is pulled up by the bottom threaded rod, so that the two floating clamping plates are close to each other. The inner hole deforms to generate clamping force to fix the spiral push shaft (6).

6. The grain crushing device with synchronous adjustment of roller gap and dual position locking according to claim 1, characterized in that: The second locking unit includes a locking seat (12) disposed on the top cover (1) and the gap adjustment tool (11); the locking seat (12) is a U-shaped structure used to accommodate the tail of the gap adjustment tool (11); the end of the gap adjustment tool (11) is connected to the end face of the spiral push shaft (6), and its tail can be inserted into the locking seat (12) and fixedly connected to the locking seat (12) by a detachable locking pin; when the gap adjustment tool (11) is fixed on the locking seat (12), the gap adjustment tool (11) restricts the rotation of the spiral push shaft (6) and the sprocket (8), thereby realizing the locking of the sprocket (8) and the chain (9).

7. The grain crushing device with synchronous adjustment of roller gap and dual position locking according to claim 1, characterized in that: It also includes a safety connecting bridge (5), which is connected between the main frame (2) and the fixed crushing roller (4), and has a hoisting hole on its top.

8. The grain crushing device with synchronous adjustment of roller gap and dual position locking according to claim 1, characterized in that: It also includes a chain tensioning mechanism (10), which includes a tensioning plate A (14), a tensioning plate B (15) and an adjusting bolt (16). The two ends of the chain (9) are connected to the tensioning plate A (14) and the tensioning plate B (15) respectively. The tensioning is achieved by adjusting the bolt (16) to push the tensioning plate A (14) closer to the tensioning plate B (15).

9. A grain crushing device with synchronous adjustment of roller gap and dual position locking according to claim 1, characterized in that: It also includes a push-pull recessed rail (13), which is located at the bottom of the main frame (2) and is a U-shaped rail structure used for sliding cooperation with the external guide rail.

10. A self-propelled forage harvester, characterized in that: The grain crushing device is equipped with the synchronous adjustment of the roller gap and the dual locking of the position as described in any one of claims 1-9.

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