A concrete mixing device for road and bridge

Abstract

The application discloses a kind of concrete mixing devices for road and bridge, it is related to concrete mixing technical field, including support, the side wall of the support is fixedly installed with driving motor, and the output shaft of one end of driving motor is fixedly connected with axle rod, the outer wall of axle rod is attached with stirring drum, and the outer wall of axle rod is fixedly connected with first stirring rod at equal intervals.This kind of concrete mixing device for road and bridge, can be driven by driving motor first stirring rod and second stirring rod respectively staggered rotation, to avoid part of concrete follow one-way movement, to ensure that the stirring efficiency of the device to concrete, simultaneously by the cooperation of helical groove and guide column, so that stirring drum will left and right horizontal shift in the stirring process Shake, so that the position of first stirring rod and second stirring rod in stirring drum can be constantly changed, to avoid dead angle, to ensure that the stirring quality of the device to concrete.

Description

Technical Field

[0001] This invention relates to the field of concrete mixing technology, specifically to a concrete mixing device for roads and bridges. Background Technology

[0002] In the construction of roads and bridges, concrete is used as the main material to pour and form building structures of any specific shape. Currently, concrete needs to be mixed by a concrete mixer before use. The concrete mixer is mainly used to mix cement, sand and gravel aggregates and water to make concrete mixture. For example, the concrete mixing device disclosed in Chinese Patent CN111391129A can effectively dissipate heat from the mixing drum and the concrete during mixing, thereby avoiding false setting of concrete due to excessive temperature. It can also weigh and measure the raw materials.

[0003] However, in the above-mentioned concrete mixing process, the mixing shaft usually drives the mixing rod to achieve the mixing effect. As a result, some concrete will move along with the rotation direction of the mixing rod during the mixing process, which leads to poor concrete mixing efficiency. At the same time, since the position of the mixing rod is fixed during the mixing process, dead corners are easy to appear in the concrete mixing, which will affect the subsequent concrete mixing quality. Summary of the Invention

[0004] The purpose of this invention is to provide a concrete mixing device for roads and bridges to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a concrete mixing device for roads and bridges, comprising a support frame, a drive motor fixedly installed on one side wall of the support frame, and a shaft fixedly connected to one end of the output shaft of the drive motor, a mixing cylinder being fitted against the outer wall of the shaft, and first mixing rods being fixedly connected at equal intervals to the outer wall of the shaft, and a reversing shaking mechanism being provided on the outer wall of the shaft;

[0006] The reversing and shaking mechanism includes a reversing component and a shaking component. The reversing component is driven by the shaking component and the reversing component is driven by the drive motor. When mixing concrete, the reversing component controls the rotation direction of the mixing drum to be opposite to that of the first mixing rod to perform staggered mixing, and the shaking component controls the mixing drum to move and shake left and right.

[0007] A crushing component is provided on one side wall of the first stirring rod so that, during the stirring process, the crushing component can be used to squeeze and crush lumps or sand and gravel in the concrete.

[0008] The outer wall of the shaft is provided with scraping components at equal intervals, and the inner wall of the mixing drum is fitted with a scraping ring, so that the scraping components and the scraping ring can be used to thoroughly scrape the inner wall of the mixing drum during the mixing process.

[0009] Preferably, the reversing component includes a transmission belt, and the inner wall of the transmission belt is rotatably connected to the outer wall of the shaft. A rotating rod is rotatably connected to the inner wall of the transmission belt, and the outer wall of the rotating rod is rotatably connected to the inside of the bracket. A first gear is fixedly connected to the outer wall of the rotating rod at equal intervals. A second gear is fixedly connected to the outer wall of the stirring cylinder corresponding to the first gear. The teeth of the first gear match the teeth of the second gear.

[0010] Preferably, the inner wall of the stirring drum is symmetrically provided with grooves, and the inner wall of the grooves is provided with second stirring rods. The outer walls of the two second stirring rods at opposite ends slide against the inner wall of the grooves, and the two second stirring rods at adjacent ends are fixedly connected with connecting rings. The outer wall of the shaft is provided with a limiting groove corresponding to the connecting ring, and the inner wall of the connecting ring rotates against the inner wall of the limiting groove. The side walls of the two second stirring rods at opposite ends are fixedly connected with fixing blocks.

[0011] Preferably, the shaking component includes a base, and the bottom of the base is fixedly connected to the bottom inner wall of the support. A guide column is fixedly connected to the top of the base. A spiral groove is opened on the outer wall of the stirring cylinder corresponding to the guide column, and the top of the guide column slides in contact with the inner wall of the spiral groove.

[0012] Preferably, the crushing component includes a groove, and a first spring is fixedly connected to the inner wall of the groove. A crushing block is fixedly connected to the other end of the first spring, and one side wall of the crushing block is inclined. The crushing block and the groove form a telescopic structure through the first spring.

[0013] Preferably, the scraping assembly includes a slider, the outer wall of the shaft is provided with transverse grooves at equal intervals corresponding to the slider, and the outer wall of the slider slides in contact with the inner wall of the transverse grooves. A limiting rod is fixedly connected to the inner wall of the transverse grooves, and the outer wall of the limiting rod slides in contact with the interior of the slider. The inner wall of the scraping ring is fixed to one end of the two first stirring rods that is far away from each other.

[0014] Preferably, a scraper is fixedly connected to the top of the limiting rod, and one side wall of the scraper is in contact with the inner wall end face of the stirring cylinder, while the other side wall of the scraper is inclined.

[0015] Preferably, a second spring is fitted to the outer wall of the limiting rod, and the two ends of the two second springs that are far apart are fixedly connected to the side wall of the two sliders that are close to each other, and the other ends of the two second springs are fixedly connected to the inner wall of the transverse groove.

[0016] Preferably, a feeding pipe is fixedly installed on one outer wall end face of the mixing drum, and a discharge pipe is fixedly installed on the other outer wall end face of the mixing drum.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. During the mixing process of concrete for road and bridge construction, the first and second mixing rods can be driven by a drive motor to rotate alternately, thereby preventing some concrete from moving in one direction and ensuring the mixing efficiency of the device. At the same time, through the cooperation of the spiral groove and the guide column, the mixing drum will move left and right and sway during the mixing process, thereby continuously changing the position of the first and second mixing rods in the mixing drum, avoiding dead corners, and thus ensuring the mixing quality of the concrete.

[0019] 2. During the mixing process of concrete for road and bridge construction, the first and second mixing rods rotate alternately, allowing multiple broken blocks to continuously contact and collide with the fixed blocks. This crushes lumps or gravel in the concrete, facilitating mixing and improving the mixing efficiency of the device.

[0020] 3. During the mixing process of concrete for road and bridge construction, the lateral movement of the mixing drum allows the scraper ring to continuously scrape the inner wall of the mixing drum. Simultaneously, the scraper rod, rotating in the opposite direction to the mixing drum, scrapes the two ends of the inner wall, preventing some concrete from solidifying on the inner wall and failing to participate in the mixing process. This also reduces the amount of adhering material on the inner wall after the mixing drum discharges, thus ensuring the mixing effect of the device. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 This is a top view of the overall structure of the present invention;

[0023] Figure 3 This is a schematic diagram of the internal structure of the stirring tank of the present invention;

[0024] Figure 4 This is a schematic diagram of the structure of the first part of the reversing swaying mechanism of the present invention;

[0025] Figure 5 This is a schematic diagram of the second part of the reversing swaying mechanism of the present invention;

[0026] Figure 6 This is a schematic diagram of the structure of the crushing component of the present invention;

[0027] Figure 7 This is a schematic diagram of the scraping component of the present invention.

[0028] In the diagram: 1. Support; 2. Drive motor; 3. Shaft; 4. Mixing drum; 5. First mixing rod; 7. Slide groove; 8. Spiral groove; 9. Limiting groove; 11. Scraper ring; 13. Horizontal groove; 14. Feeding pipe; 15. Discharge pipe; 6. Reversing shaking mechanism; 601. Transmission belt; 602. Rotating rod; 603. First gear; 604. Second gear; 605. Second mixing rod; 606. Connecting ring; 607. Base; 608. Guide column; 609. Fixing block; 10. Crushing assembly; 1001. Groove; 1002. First spring; 1003. Crushing block; 12. Scraping assembly; 1201. Slider; 1202. Limiting rod; 1203. Scraper; 1204. Second spring. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1, please refer to Figure 1-7 The present invention provides a technical solution: a concrete mixing device for road and bridge construction, comprising a support 1 and a shaft 3, wherein a drive motor 2 is fixedly installed on one side wall of the support 1, and a reversing shaking mechanism 6 is provided on the outer wall of the shaft 3;

[0031] The reversing and shaking mechanism 6 includes a reversing component and a shaking component. The reversing component and the shaking component are driven by each other. The reversing component is driven by the drive motor 2. When mixing concrete, the reversing component controls the rotation direction of the mixing drum 4 to be opposite to that of the first mixing rod 5 to perform staggered mixing. The shaking component controls the mixing drum 4 to move and shake left and right.

[0032] Furthermore, the reversing component includes a drive belt 601, and the outer wall of the rotating rod 602 is rotatably connected to the inside of the bracket 1;

[0033] In this embodiment, during the mixing process of concrete for road and bridge construction, a feeding pipe 14 is first fixedly installed on one outer wall end face of the mixing drum 4, and a discharge pipe 15 is fixedly installed on the other outer wall end face of the mixing drum 4. Concrete material can be fed into the mixing drum 4 through the feeding pipe 14. After the feeding is completed, the drive motor 2 is started. A shaft 3 is fixedly connected to one end of the output shaft of the drive motor 2, and first stirring rods 5 are fixedly connected at equal intervals on the outer wall of the shaft 3. Thus, the drive motor 2 can drive multiple first stirring rods 5 to stir the concrete material in the mixing drum 4.

[0034] Next, during the stirring process, the inner wall of the transmission belt 601 is rotatably connected to the outer wall of the shaft 3, and the inner wall of the transmission belt 601 is rotatably connected to the rotating rod 602. Thus, the rotation of the shaft 3 drives the transmission belt 601 to rotate and move, thereby driving the rotating rod 602 to rotate in the same direction as the shaft 3. Then, the outer wall of the rotating rod 602 is fixedly connected to the first gear 603 at equal intervals, and the outer wall of the stirring drum 4 is fixedly connected to the first gear 603. The teeth of the first gear 603 match the teeth of the second gear 604, so that the rotating rod 602 drives the first gear 603 to rotate, and the first gear 603 drives the second gear 604 to rotate in the opposite direction, so that the rotation direction of the stirring drum 4 is opposite to that of the first stirring rod 5.

[0035] Next, symmetrical grooves 7 are provided on the inner wall of the mixing drum 4, and second mixing rods 605 are provided on the inner wall of the grooves 7. The outer walls of the two second mixing rods 605 that are far apart slide against the inner wall of the grooves 7, while the two second mixing rods 605 that are close together are fixedly connected to a connecting ring 606. The outer wall of the shaft 3 is provided with a limiting groove 9 corresponding to the connecting ring 606, and the inner wall of the connecting ring 606 rotates against the inner wall of the limiting groove 9. This allows the mixing drum 4 to drive the second mixing rods 605 to rotate in the opposite direction around the shaft 3 through the cooperation of the grooves 7 and the limiting groove 9. This causes the first mixing rod 5 and the second mixing rod 605 to rotate alternately, thereby preventing some concrete from moving in one direction.

[0036] Next, during the mixing process, the bottom of the base 607 is fixedly connected to the bottom inner wall of the support 1, and the top of the base 607 is fixedly connected to the guide column 608. The outer wall of the mixing drum 4 is provided with a spiral groove 8 corresponding to the guide column 608. At the same time, the top of the guide column 608 slides against the inner wall of the spiral groove 8. Thus, when the mixing drum 4 rotates, the guide column 608 and the spiral groove 8 cooperate to make the mixing drum 4 rotate and move left and right at the same time. This can drive the concrete material in the mixing drum 4 to move relative to the first mixing rod 5 and the second mixing rod 605, so that the mixing range is larger and more comprehensive.

[0037] As described above, during the mixing process of concrete for this road and bridge project, the drive motor 2 can drive the first mixing rod 5 and the second mixing rod 605 to rotate alternately, thereby preventing some concrete from moving in one direction and ensuring the mixing efficiency of the device. At the same time, through the cooperation of the spiral groove 8 and the guide column 608, the mixing drum 4 will move laterally left and right during the mixing process, thereby continuously changing the position of the first mixing rod 5 and the second mixing rod 605 inside the mixing drum 4, avoiding dead corners, and thus ensuring the mixing quality of the concrete by the device.

[0038] Example 2, based on the above examples:

[0039] A crushing component 10 is provided on one side wall of the first mixing rod 5 so that during the mixing process, the crushing component 10 can be used to crush lumps or sand and gravel in the concrete.

[0040] Furthermore, the crushing component 10 includes a groove 1001, and a first spring 1002 is fixedly connected to the inner wall of the groove 1001, and a crushing block 1003 is fixedly connected to the other end of the first spring 1002, while one side wall of the crushing block 1003 is inclined.

[0041] In this embodiment, during the mixing process of the concrete for this road and bridge, when the first mixing rod 5 and the second mixing rod 605 rotate alternately, a first spring 1002 is fixedly connected to the inner wall of the groove 1001, and a crushing block 1003 is fixedly connected to the other end of the first spring 1002. Thus, when the first mixing rod 5 moves in a circular motion, it will synchronously drive the crushing block 1003 to move. At this time, a fixing block 609 is fixedly connected to the side wall of the two second mixing rods 605 that are far apart, so that the crushing block 1003 and the fixing block 609 can collide with each other, thereby squeezing and crushing the lumps or sand and gravel in the concrete, which facilitates the mixing of the concrete.

[0042] Next, the contact and collision surfaces of the fixed block 609 and the broken block 1003 are inclined, and the broken block 1003 forms a telescopic structure with the first spring 1002 and the groove 1001. Thus, during the collision process, the inclined surface guides the broken block 1003 to retract into the groove 1001 and compress the first spring 1002. After the collision, the rebound of the first spring 1002 will drive the broken block 1003 to return to its original position.

[0043] As described above, during the mixing process of concrete for this road and bridge, the first mixing rod 5 and the second mixing rod 605 can rotate alternately, so that multiple broken blocks 1003 can continuously contact and collide with the fixed block 609, thereby squeezing and breaking up lumps or sand and gravel in the concrete, facilitating the mixing of concrete and thus improving the mixing efficiency of this device.

[0044] Example 3, based on the above examples:

[0045] Scraping components 12 are provided at equal intervals on the outer wall of the shaft 3, and scraping rings 11 are provided on the inner wall of the mixing drum 4, so that the scraping components 12 and scraping rings 11 can be used to scrape the inner wall of the mixing drum 4 during the mixing process.

[0046] Furthermore, the scraping assembly 12 includes a slider 1201, and the outer wall of the shaft 3 is provided with transverse grooves 13 at equal intervals corresponding to the slider 1201. The outer wall of the slider 1201 slides in contact with the inner wall of the transverse groove 13. Then, the inner wall of the transverse groove 13 is fixedly connected to a limiting rod 1202, and the outer wall of the limiting rod 1202 slides in contact with the interior of the slider 1201. The inner wall of the scraping ring 11 is fixed to one end of the two first stirring rods 5 that are far apart from each other.

[0047] In this embodiment, during the mixing process of concrete for road and bridge construction, a scraper ring 11 is attached to the inner wall of the mixing drum 4, and the inner wall of the scraper ring 11 is fixed to the ends of the two first mixing rods 5 that are far apart. This allows the inner wall of the mixing drum 4 to be completely scraped by the scraper ring 11 during the mixing process when the mixing drum 4 moves left and right.

[0048] Next, during the stirring process, the outer wall of the slider 1201 slides against the inner wall of the transverse groove 13, and a limiting rod 1202 is fixedly connected to the inner wall of the transverse groove 13. The outer wall of the limiting rod 1202 slides against the interior of the slider 1201. Simultaneously, a scraper 1203 is fixedly connected to the top of the limiting rod 1202, and one side wall of the scraper 1203 is against the end face of the inner wall of the stirring drum 4. The other side wall of the scraper 1203 is inclined. Since the rotation direction of the shaft 3 is opposite to the rotation direction of the stirring drum 4, the stirring process can be achieved by... The scraper 1203 scrapes the two ends of the inner wall of the mixing drum 4. At the same time, when the mixing drum 4 moves left and right, the second spring 1204 is attached to the outer wall of the limiting rod 1202. The two ends of the two second springs 1204 are fixedly connected to the side wall of the two sliders 1201 that are close to each other. The other ends of the two second springs 1204 are fixedly connected to the inner wall of the transverse groove 13. Thus, the position of the scraper 1203 can be controlled by the second springs 1204, so that it can be tightly attached to the two ends of the inner wall of the mixing drum 4, ensuring the scraping effect.

[0049] When mixing is complete, turn off the drive motor 2 and remove the concrete material through the discharge pipe 15.

[0050] As described above, during the mixing process of concrete for this road and bridge, the lateral movement of the mixing drum 4 during the mixing process allows the scraper ring 11 to continuously scrape the inner wall of the mixing drum 4. At the same time, the scraper rod 1203, which rotates in the opposite direction to the mixing drum 4, scrapes the two ends of the inner wall of the mixing drum 4. This prevents some concrete from solidifying on the inner wall of the mixing drum 4 without participating in the mixing process, and reduces the amount of adhering material on the inner wall of the mixing drum 4 after discharge, thereby ensuring the mixing effect of this device.

[0051] Working principle: In the process of mixing concrete for road and bridge construction, concrete material is first fed into the mixing drum 4 through the feeding pipe 14. After the feeding is completed, the drive motor 2 is started. A shaft 3 is fixedly connected to one end of the output shaft of the drive motor 2, and the outer wall of the shaft 3 is fixedly connected with the first stirring rod 5 at equal intervals. Thus, the drive motor 2 can drive multiple first stirring rods 5 to mix the concrete material in the mixing drum 4.

[0052] Next, during the mixing process, the rotation of the shaft 3 drives the transmission belt 601 to rotate, causing the rotating rod 602 to rotate in the same direction as the shaft 3. This allows the rotating rod 602 to drive the first gear 603 to rotate, which in turn drives the second gear 604 to rotate in the opposite direction. This makes the rotation direction of the mixing drum 4 opposite to that of the first mixing rod 5. At this time, the mixing drum 4 can drive the second mixing rod 605 to rotate in the opposite direction around the shaft 3 through the cooperation of the sliding groove 7 and the limiting groove 9. This allows the first mixing rod 5 and the second mixing rod 605 to rotate alternately, thereby preventing some concrete from moving in one direction.

[0053] Then, during the mixing process, when the mixing drum 4 rotates, the guide column 608 and the spiral groove 8 can cooperate to make the mixing drum 4 rotate and move left and right at the same time, thereby driving the concrete material in the mixing drum 4 to move relative to the first mixing rod 5 and the second mixing rod 605, so that the mixing range is larger and more comprehensive.

[0054] Then, when the first stirring rod 5 and the second stirring rod 605 rotate alternately, they will synchronously drive the broken block 1003 to move. At this time, a fixed block 609 is fixedly connected to the side wall of the two second stirring rods 605 that are far apart, so that the broken block 1003 and the fixed block 609 can collide with each other, thereby squeezing and breaking up the lumps or sand and gravel in the concrete, which facilitates the mixing of the concrete. During the collision process, the broken block 1003 is guided by the inclined plane to shrink into the groove 1001 and compress the first spring 1002. After the collision, the broken block 1003 will return to its original position by the rebound of the first spring 1002.

[0055] Then, when the mixing drum 4 moves left and right, the scraper ring 11 can continuously scrape the inner wall of the mixing drum 4 during the mixing process. At the same time, since the rotation direction of the shaft 3 is opposite to the rotation direction of the mixing drum 4, the scraper rod 1203 can scrape the two ends of the inner wall of the mixing drum 4 during the mixing process. The position of the scraper rod 1203 can be controlled by the second spring 1204 so that it can be tightly attached to the two ends of the inner wall of the mixing drum 4, ensuring the scraping effect.

[0056] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A concrete mixing device for roads and bridges, comprising a support frame (1), characterized in that: A drive motor (2) is fixedly installed on one side wall of the bracket (1), and a shaft (3) is fixedly connected to one end of the output shaft of the drive motor (2). A stirring cylinder (4) is attached to the outer wall of the shaft (3), and a first stirring rod (5) is fixedly connected at equal distances to the outer wall of the shaft (3). A reverse shaking mechanism (6) is provided on the outer wall of the shaft (3). The reverse shaking mechanism (6) includes a reverse component and a shaking component. The reverse component and the shaking component are driven to each other so that when mixing concrete, the reverse component controls the rotation direction of the mixing drum (4) to be opposite to that of the first mixing rod (5) to perform staggered mixing, and the shaking component controls the mixing drum (4) to move and shake left and right. A crushing component (10) is provided on one side wall of the first stirring rod (5). The crushing component (10) includes a groove (1001), and a first spring (1002) is fixedly connected to the inner wall of the groove (1001). A crushing block (1003) is fixedly connected to the other end of the first spring (1002), and one side wall of the crushing block (1003) is inclined. The crushing block (1003) forms a telescopic structure with the groove (1001) through the first spring (1002). The outer wall of the shaft (3) is provided with scraping components (12) at equal intervals, and the inner wall of the stirring drum (4) is provided with scraping rings (11) so that the inner wall of the stirring drum (4) can be completely scraped by the scraping components (12) and scraping rings (11) during the stirring process. The reversing component includes a transmission belt (601), and the inner wall of the transmission belt (601) is rotatably connected to the outer wall of the shaft (3). A rotating rod (602) is rotatably connected to the inner wall of the transmission belt (601), and the outer wall of the rotating rod (602) is rotatably connected to the inside of the bracket (1). A first gear (603) is fixedly connected at equal intervals to the outer wall of the rotating rod (602). A second gear (604) is fixedly connected to the outer wall of the stirring cylinder (4) corresponding to the first gear (603). The teeth of the first gear (603) match the teeth of the second gear (604). The stirring cylinder (4) The inner wall of the shaft (3) is symmetrically provided with grooves (7), and the inner wall of the grooves (7) is provided with second stirring rods (605). The outer wall of the two second stirring rods (605) at the far end slides against the inner wall of the groove (7). The two second stirring rods (605) at the near end are fixedly connected with connecting rings (606). The outer wall of the shaft (3) is provided with a limiting groove (9) corresponding to the connecting ring (606), and the inner wall of the connecting ring (606) rotates against the inner wall of the limiting groove (9). The side wall of the two second stirring rods (605) at the far end is fixedly connected with a fixing block (609). The scraping assembly (12) includes a slider (1201). The outer wall of the shaft (3) is provided with transverse grooves (13) at equal intervals corresponding to the slider (1201). The outer wall of the slider (1201) slides in contact with the inner wall of the transverse groove (13). The inner wall of the transverse groove (13) is fixedly connected to a limiting rod (1202). The outer wall of the limiting rod (1202) slides in contact with the interior of the slider (1201). The inner wall of the scraping ring (11) is fixed to one end of the two first stirring rods (5) that are far apart from each other.

2. The concrete mixing device for roads and bridges according to claim 1, characterized in that, The swaying component includes a base (607), and the bottom of the base (607) is fixedly connected to the bottom inner wall of the bracket (1), and the top of the base (607) is fixedly connected to a guide post (608).

3. A concrete mixing device for roads and bridges according to claim 2, characterized in that, The outer wall of the stirring cylinder (4) is provided with a spiral groove (8) corresponding to the guide column (608), and the top of the guide column (608) slides in contact with the inner wall of the spiral groove (8).

4. A concrete mixing device for roads and bridges according to claim 3, characterized in that, The top of the limiting rod (1202) is fixedly connected to a scraper (1203), and one side wall of the scraper (1203) is in contact with the inner wall end face of the stirring cylinder (4), while the other side wall of the scraper (1203) is inclined.

5. A concrete mixing device for roads and bridges according to claim 4, characterized in that, The outer wall of the limiting rod (1202) is fitted with a second spring (1204). The two ends of the two second springs (1204) that are far apart are fixedly connected to the side wall of the two sliders (1201) that are close to each other. The other ends of the two second springs (1204) are fixedly connected to the inner wall of the transverse groove (13).

6. A concrete mixing device for roads and bridges according to claim 5, characterized in that, A feeding pipe (14) is fixedly installed on one outer wall end face of the mixing drum (4), and a discharge pipe (15) is fixedly installed on the other outer wall end face of the mixing drum (4).

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