JP4486067B2 - Screed adjustment mechanism in road paving machine - Google Patents

Description

  The present invention relates to a screed adjustment mechanism in a road paving machine, and in particular, it is possible to efficiently adjust the crown amount in a road paving machine equipped with a center support, and to save labor and manpower. The present invention relates to a screed adjusting mechanism in a road pavement machine.

  As a conventional technique related to a screed adjustment mechanism in a road paving machine, for example, the following spread leveling machine is known. In this prior art, left and right screeds are attached to a pair of frames via guide members or the like. The pair of frames are configured such that the inclination angle can be adjusted with the connecting shaft as the center of rotation by changing the separation distance of the upper portion by a distance adjusting mechanism. A turnbuckle is applied to the distance adjusting mechanism. The adjustment of the crown amount is performed by changing the inclination angle of the pair of frames with the connecting shaft as the center of rotation, that is, the inclination angle of the left and right screeds by the interval adjusting mechanism (see, for example, Patent Document 1).

  FIG. 7 shows a conventional crawler traveling type large road pavement machine 1. The road paving machine 1 is provided with a hopper 3 at the front part of the machine body 2 for receiving asphalt mixture from a dump truck (not shown). The asphalt mixture received by the hopper 3 is sent to the rear part of the machine body 2 by a conveyor (not shown), and the delivered asphalt mixture is spread in the width direction of the machine body 2 by a screw (not shown) and is provided with a pair of left and right. The screeds 4 and 4 are spread on the roadbed and leveled.

  As shown in FIG. 8, the left and right screeds 4, 4 are each composed of a main screed 4 </ b> A and an extension screed 4 </ b> B. 5 is provided.

  In the case of the large road pavement machine 1, the leveling width spread by the left and right screeds 4 and 4 becomes wider. For this reason, in order to maintain the flatness of the paved surface, a plurality of supports 6a to 6c are installed to support the left and right extension screeds 4B and 4B from the outer surfaces of the left and right main screeds 4A and 4A.

  A center support 6A is provided above the left and right main screeds 4A and 4A so that loads input to the supports 6a to 6c are balanced on the left and right. The center support 6A is installed between the left and right screeds 4 and 4 via support pins 7 and appropriate attachment members. A strong truss structure is constructed by the plurality of supports 6a to 6c and the center support 6A.

  Above the screed center pin 5, that is, the upper separated portion of the left and right screeds 4, 4, the inclination angle of the lower surfaces of the left and right screeds 4, 4 with the screed center pin 5 as a rotation center is adjusted. A crown adjusting portion 8 for setting the crown amount is provided. On the other hand, the center support 6A is provided with a support adjusting portion 9 having a support side turnbuckle 9a as a length varying means in order to vary the length of the center support 6A.

  Here, as shown in FIG. 10, the crown amount (%) is the ratio of the change height h of the outer end of the screed 4 to the length L from the screed center pin 5 to the outer end of the screed 4 (h / L) is a numerical value expressed in percent (%).

  FIG. 9 is an enlarged plan view showing a detailed configuration of the crown adjusting portion 8. Two crown pins 10a and 10a are attached to the left screed 4 via brackets 11a and 11a, respectively, and the two crown pins 10b and 10b are right screed via brackets 11b and 11b, respectively. 4 is attached.

  Between the two facing crown pins 10a and 10b on the front side, a span-side turnbuckle 12A is spanned as a span varying means for varying the support span of the two crown pins 10a and 10b. Further, a span-side turnbuckle 12B as a span varying means for varying the support span of the two crown pins 10a, 10b is installed between the two opposed crown pins 10a, 10b on the rear side.

  A ratchet trench 13 for operating the span-side turnbuckle 12B is attached to the turnbuckle shaft 12b of the span-side turnbuckle 12B. Between the turnbuckle shaft 12b in the span-side turnbuckle 12B and the turnbuckle shaft 12a in the other span-side turnbuckle 12A, power transmission means comprising two sprockets 14a, 14b and a chain 15 is installed. Yes.

  By the operation of the ratchet trench 13, the front and rear span turnbuckles 12A and 12B are operated simultaneously by the power transmission means, and the upper spacing distance between the left and right screeds 4 and 4 is varied.

  When the crown adjustment unit 8 adjusts the crown amount to the negative side, the tension of the center support 6A installed between the left and right screeds 4 and 4 while rotating the ratchet trench 13 in one direction. The state is confirmed, and if necessary, the length of the center support 6A is adjusted to be shorter by the support adjusting unit 9 to set the crown amount to the required amount on the minus side.

  When the crown amount is adjusted to the plus side, the tension state of the center support 6A is confirmed while rotating the ratchet trench 13 in the other direction, and the length of the center support 6A is supported if necessary. Long adjustment is performed by the adjusting unit 9 to set the crown amount to the required amount on the plus side.

As described above, when the crown amount is adjusted, the crown adjusting portion 8 and the support adjusting portion 9 are operated at the same time, or the center support 6A is removed at the portion of the support pin 7, and then the crown amount is determined only by the crown adjusting portion 8. It is necessary to make adjustments.
JP-A-11-256513 (pages 3, 4 and 5).

  In the prior art described in Patent Document 1, there is no center support provided on the road pavement machine, and only an interval adjusting mechanism for changing the upper spacing between the left and right screeds when adjusting the crown amount is shown.

  Further, in the prior art shown in FIGS. 7 to 10, when the crown amount is adjusted, the crown adjusting unit and the support adjusting unit are operated simultaneously by a plurality of persons, or in the case of a single operation, the center support is provided. It was necessary to operate the crown adjuster after removing the support pin. For this reason, adjustment work time became long and the construction efficiency was reduced, and it was difficult to save labor and manpower.

  Therefore, there is a technical problem to be solved in order to improve the pavement quality and smoothly adjust the crown amount to shorten the adjustment work time, save labor, and save labor. It aims at solving this subject.

  The present invention has been proposed in order to achieve the above object, and the invention according to claim 1 is a crown for adjusting the crown amount of the left and right screeds by changing the upper spacing distance between the left and right screeds by a span varying means. A length varying means for varying the length of the center support provided between the adjustment section and the left and right screeds, and the center support of the center support by the length varying means according to a crown adjustment amount by the crown adjustment section. A screed adjustment mechanism in a road pavement machine having a support adjustment unit for adjusting a length, wherein a single actuator is connected to the span variable means and the length variable means via power transmission means, respectively. The crown amount and the center support length are adjusted simultaneously by the driving force of one actuator. Providing screed adjusting mechanism in a road paving machine comprising Te.

  According to this configuration, the setting of the crown amount is performed by operating the span varying means to adjust the inclination angles of the lower surfaces of the left and right screeds with the screed center pin as the center of rotation. When setting the crown amount, it is necessary to simultaneously adjust the length of the center support provided between the left and right screeds. On the other hand, the center support length is automatically adjusted at the same time when the crown amount is adjusted by driving the length varying means together with the span varying means with a single actuator.

  The invention according to claim 2 provides a screed adjustment mechanism in a road paving machine, wherein the actuator is either a hydraulic motor or an electric motor.

  According to this configuration, the actuator is operated by a simple operation such as a switch operation, and the length of the center support is adjusted at the same time when the crown amount is adjusted.

  According to a third aspect of the present invention, the span varying means is a span-side turnbuckle, and the power transmission means for connecting the span-side turnbuckle and the single actuator is a turn in the span-side turnbuckle. A span-side sprocket on the buckle shaft; an actuator sprocket on the output shaft of the actuator; and a chain spanned between the span-side sprocket and the actuator sprocket. The power transmission means for connecting between the support-side turnbuckle and the single actuator includes a support-side sprocket on a turnbuckle shaft in the support-side turnbuckle, and an actuator on an output shaft in the actuator. Providing a sprocket, the screed adjusting mechanism in a road paving machine which is composed of a multiplying passed chain between the support-side sprocket and the actuator sprockets.

  According to this configuration, a turn buckle is specifically used as the span variable means and the length variable means, respectively, and a sprocket and chain combination mechanism is used as the power transmission means to drive a single actuator. The force is transmitted to each turnbuckle as the span variable means and the length variable means, and the length of the center support is automatically adjusted simultaneously when the crown amount is adjusted.

  According to a fourth aspect of the present invention, an error occurring in an adjustment margin of the center support length due to driving of the span varying means and the length varying means by driving the single actuator, the span side sprocket and the support side There is provided a screed adjustment mechanism in a road pavement machine that compensates for at least one of a gear ratio with a sprocket or a screw pitch difference between the span-side turnbuckle and the support-side turnbuckle.

  According to this configuration, the distance from the screed center pin that is the rotation center of the left and right screeds to the crown pin in the span variable means is different from the distance from the screed center pin to the support pin at the center support end, etc. Due to structural differences between the mechanism side and the center support mechanism side, when the span variable means and the length variable means are driven simultaneously by a single actuator, the center support length for the required adjustment allowance by the span variable means An error generally occurs in the adjustment allowance. On the other hand, by adjusting at least one of the gear ratio between the span-side sprocket and the support-side sprocket or the screw pitch difference between the span-side turnbuckle and the support-side turnbuckle, the center support length adjustment allowance is increased. The error is absorbed.

  According to a fifth aspect of the present invention, there is provided a crown adjusting portion for adjusting a crown amount of the left and right screeds by changing an upper spacing distance between the left and right screeds by a span varying means, and a center support provided between the left and right screeds. A screed adjustment in a road pavement machine, comprising: a length adjusting means for changing the length of the center support; and a support adjusting portion for adjusting the length of the center support by the length changing means according to a crown adjustment amount by the crown adjusting portion. A first hydraulic motor connected to the span variable means via a power transmission means, a second hydraulic motor connected to the length variable means via another power transmission means, The first hydraulic motor and the second hydraulic motor are connected in parallel to a hydraulic power source and operated simultaneously to adjust the crown amount and the center support length. Providing screed adjusting mechanism in a road paving machine comprising configured to perform preparative simultaneously.

  According to this configuration, the first hydraulic motor that drives the span variable means and the second hydraulic motor that drives the length variable means are connected in parallel to the hydraulic power source and operated simultaneously, so that the first The hydraulic motor and the second hydraulic motor operate to output motors corresponding to the loads on the crown mechanism side and the support mechanism side, respectively. As a result, the center support length is appropriately adjusted appropriately to properly adjust the required crown amount.

  According to the first aspect of the present invention, a single actuator is connected to the span variable means and the length variable means via the power transmission means, respectively, and the crown amount is adjusted and the center support length is adjusted by the driving force of the single actuator. Since the center support length is automatically adjusted when adjusting the crown amount, it is possible to improve the pavement quality and shorten the adjustment time of the crown amount. There is an advantage that labor saving and manpower saving can be achieved.

  In the invention according to claim 2, since the actuator is either a hydraulic motor or an electric motor, the crown amount can be adjusted by a simple operation such as a switch operation while looking at the leveled pavement surface during construction. Thus, there is an advantage that the pavement quality can be improved.

  According to a third aspect of the present invention, the span varying means is a span-side turnbuckle, and the power transmission means for connecting the span-side turnbuckle and the single actuator is a turn in the span-side turnbuckle. A span-side sprocket on the buckle shaft; an actuator sprocket on the output shaft of the actuator; and a chain spanned between the span-side sprocket and the actuator sprocket. The power transmission means for connecting between the support-side turnbuckle and the single actuator includes a support-side sprocket on a turnbuckle shaft in the support-side turnbuckle, and an actuator on an output shaft in the actuator. Since it is composed of a sprocket and a chain spanned between the support side sprocket and the actuator sprocket, the driving force of a single actuator is reliably transmitted to each turnbuckle as span variable means and length variable means. Thus, there is an advantage that the center support length can be automatically adjusted simultaneously when the crown amount is adjusted.

  According to a fourth aspect of the present invention, an error occurring in an adjustment margin of the center support length due to driving of the span varying means and the length varying means by driving the single actuator, the span side sprocket and the support side Since the gear ratio with the sprocket or the screw pitch difference between the span-side turnbuckle and the support-side turnbuckle is corrected, the span variable means and the length variable means can be adjusted simultaneously with a single actuator. When driven, there is an advantage that an error occurring in the adjustment allowance for the center support length can be absorbed, and the crown amount can be adjusted smoothly.

  According to a fifth aspect of the present invention, the first hydraulic motor is connected to the span variable means via the power transmission means, the second hydraulic motor is connected to the length variable means via the other power transmission means, Since the first hydraulic motor and the second hydraulic motor are connected to a hydraulic power source in parallel and operated simultaneously, the crown amount is adjusted and the center support length is adjusted at the same time. At this time, there is an advantage that adjustment of the center support length appropriately corresponding to the adjustment of the crown amount is automatically performed, and the adjustment of the crown amount can be performed extremely smoothly.

  In order to improve the pavement quality and smoothly adjust the crown amount to shorten the adjustment work time, save labor, and save labor, the upper spacing distance between the left and right screeds can be changed with a span variable means. A crown adjusting portion for changing the crown amount of the left and right screeds, and a length adjusting means for changing the length of a center support provided between the left and right screeds. A screed adjustment mechanism in a road pavement machine having a support adjustment unit that adjusts the length of the center support by the length variable means according to the above, wherein a single actuator is used as the span variable means and the length variable means. Are connected via power transmission means, and the crown amount is adjusted by the driving force of the single actuator. It was realized by performing the center support length adjustment and at the same time as.

  Embodiment 1 of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of a screed adjustment mechanism in a road paving machine, (a) is a plan view, (b) is a view of FIG. (A) viewed from the rear side, and FIG. 2 is a view in FIG. It is an expansion schematic sectional drawing in alignment with XX. 1 and 2 and FIG. 5 and FIG. 6 showing Example 2 to be described later, the same or equivalent components in FIG. 8 and FIG. 9 are denoted by the same reference numerals as those in FIG. To do.

  First, the configuration of the screed adjusting mechanism in the road paving machine according to the present embodiment will be described. In the present embodiment, the crown adjusting portion 8 from which the manual ratchet trench shown in FIG. 9 is removed is disposed in the upper separated portion of the left and right main screeds 4A, 4A. On the other hand, a support-side turnbuckle 9a as a length varying means in the support adjusting unit 9 includes a center support 6A that also serves as a turnbuckle shaft, and a left screw portion and a right screw portion that are provided at both left and right ends of the center support 6A. It consists of and.

  The span-side turnbuckles 12A and 12B as the span changing means in the crown adjusting portion 8 and the support-side turnbuckle 9a in the support adjusting portion 9 are simultaneously provided by an actuator 16 composed of a single hydraulic motor or electric motor. It is configured to be driven.

  The single actuator 16 is connected to the span-side turnbuckles 12A and 12B and the support-side turnbuckle 9a through each power transmission means as follows.

  That is, the actuator sprocket 17 on the output shaft 16 a in the actuator 16, the span side sprocket 18 on the turn buckle shaft 12 a in the span side turnbuckle 12 A, and the chain spanned between the actuator sprocket 17 and the span side sprocket 18. 19 constitutes a first power transmission means 20.

  The span-side sprocket 21 on the turnbuckle shaft 12b in the span-side turnbuckle 12B, the support-side sprocket 22 on the center support 6A (turnbuckle shaft) in the support-side turnbuckle 9a, the span-side sprocket 21 and the support-side sprocket The second power transmission means 24 is constituted by the chain 23 spanned between 22.

  Inside the crown adjusting portion 8, an internal power transmission means 25 composed of two sprockets 14 a and 14 b and a chain 15 is provided.

  The output shaft 16a of the single actuator 16 is connected to the span-side turnbuckle 12A in the crown adjusting portion 8 via the first power transmission means 20.

  Further, the output shaft 16 a of the single actuator 16 is connected to the support side turnbuckle 9 a in the support adjustment unit 9 by the first power transmission unit 20 and the internal power transmission unit 25 in the crown adjustment unit 8. And the second power transmission means 24.

  As shown in FIG. 1B, the distance R1 from the screed center pin 5 that is the rotation center of the left and right screeds including the left and right main screeds 4A and 4A to the crown pin 10b in the crown adjusting portion 8, and the screed center. There is a structural difference between the crown mechanism side and the center support mechanism side, such as different from the distance R2 from the pin 5 to the support pin 7 at the end of the center support 6A.

  For this reason, when the span-side turnbuckles 12A and 12B in the crown adjusting unit 8 and the support-side turnbuckle 9a in the support adjusting unit 9 are simultaneously driven by a single actuator 16, a necessary adjustment allowance by the crown adjusting unit 8 ( In general, an error occurs in the allowance for adjusting the length of the center support 6A by the support adjusting unit 9 with respect to the amount of expansion.

  In order to absorb this error, a necessary correction is required for at least one of the gear ratio between the span-side sprockets 18 and 21 and the support-side sprocket 22 or the screw pitch difference between the span-side turnbuckles 12A and 12B and the support-side turnbuckle 9a. It has been added.

  Next, the operation of the screed adjustment mechanism in the road paving machine configured as described above will be described.

  As described above, when the span-side turnbuckles 12A and 12B and the support-side turnbuckle 9a are simultaneously driven by the single actuator 16, this is caused by the structural difference between the crown mechanism side and the center support mechanism side. In order to absorb the error, a necessary correction is added to the gear ratio between the span side sprockets 18 and 21 and the support side sprocket 22.

However, common in FIG. 1 (b), the left and right main screed 4A, when a horizontal state of 4A, the screed center pin 5 and the angle theta ₁ viewed crown pin 10b, and the angle theta ₂ viewed support pin 7 Different. The adjustment allowance (extension amount) by the crown adjustment unit 8 and the adjustment allowance for the length of the center support 6A by the support adjustment unit 9 are obtained by the relationship of the trigonometric functions of the angles θ ₁ and θ ₂ , and both adjustment allowances Is not directly proportional. For this reason, even if correction is made to the gear ratio between the span side sprocket 21 and the support side sprocket 22, an error still occurs between the adjustment margins.

  The occurrence of this error will be described with reference to FIGS. 3 and 4 and Tables 1 and 2. FIG. 3 is a diagram showing the relationship between the adjustment margin of the span side turnbuckles 12A and 12B and the length of the center support 6A, and FIG. 4 shows the relationship between the adjustment angle Δθ and the adjustment margin of the center support adjustment margin and the span side turnbuckle adjustment margin. The shown figures, Table 1 and Table 2 summarize the numerical examples in FIGS. 3 and 4.

In FIG. 1B, the distance R ₁ from the screed center pin 5 to the crown pin 10 b and the distance R ₂ from the screed center pin 5 to the support pin 7 are R ₁ ≠ R ₂ , and the angle θ ₁ the theta _2, theta ₁ for ≠ theta _2, crown crown pin 10a by the adjustment unit 8, the expansion amount 2.DELTA.L ₁ between 10b and (right total), the expansion amount 2.DELTA.L between the support pins 7,7 supported by adjuster 9 ₂ (left and right total) is expressed by the following formulas (1) and (2) including trigonometric functions.

2ΔL ₁ = 2R ₁ [cos (θ ₁ −Δθ ₁ ) −cos θ ₁ ] (1)
2ΔL ₂ = 2R ₂ [cos (θ ₂ −Δθ ₂ ) −cos θ ₂ ] (2)
Now, the adjustment ratio (ΔL ₂ / ΔL ₁ ) of 1.190 in Table 2 is adopted as the gear ratio (rotational speed ratio) between the span-side sprocket 21 and the support-side sprocket 22 in the second power transmission means 24. In this case, when the crown amount is + 5%, the extension amount between the crown pins 10a and 10b is +91.9 mm, the extension amount between the support pins 7 and 7 is +109.4 mm, and the difference is 17.5 mm. As a result, when the crown amount is between 0% and + 5%, the adjustment of the crown amount in the simultaneous crown / support adjustment is smoothly performed without any problem.

Further, when the crown amount is between 0% and -1%, the crown adjustment portion 8 is adjusted smoothly with respect to the extension amount between the crown pins 10a and 10b -18.5 mm when the crown amount is -1%. The extension amount between the support pins 7 and 7 needs to be −22.6 mm. However, since the gear ratio between the span side sprocket 21 and the support side sprocket 22 is fixed at 1.190,
−22.6 − (− 18.5 × 1.190) = − 22.6−22.0 = 0.6 mm (3)
Thus, the extension amount between the support pins 7 is insufficient by 0.6 mm. However, such a shortage of the extension amount between the support pins 7 and 7 can be sufficiently absorbed by the backlash of the engagement portion of the drive transmission means and the fitting portion of the pin or the like. Therefore, even when the crown amount is between 0% and -1%, the crown amount is adjusted in the simultaneous crown-support simultaneous adjustment without any problem.

  In this way, by setting the adjustment range of the crown amount within a range that is structurally acceptable, the adjustment of the crown amount in the simultaneous adjustment of the crown adjustment unit 8 and the support adjustment unit 9 by driving the single actuator 16 is smooth. To be done.

  As described above, in the screed adjustment mechanism in the road paving machine according to the present embodiment, the length of the center support 6A is automatically adjusted when the crown amount is adjusted, thereby reducing the adjustment time of the crown amount. Labor saving and labor saving can be achieved.

  While looking at the leveled pavement surface during construction, the actuator 16 can be driven by a simple operation such as a switch operation to adjust the crown amount, and the pavement quality can be improved.

  A single actuator 16 can absorb the error generated in the adjustment margin of the center support length when the span side turnbuckles 12A and 12B and the support side turnbuckle 9a are driven simultaneously, and the crown amount can be adjusted smoothly. It can be carried out.

  A second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a schematic configuration diagram of the screed adjustment mechanism, (a) is a plan view, (b) is a view of FIG. (A) as viewed from the rear side, and FIG. 6 is a first hydraulic motor and a second hydraulic motor. It is a hydraulic circuit diagram which shows the connection relationship of.

  In this embodiment, the output shaft of the first hydraulic motor 26 is connected to the span-side turnbuckles 12A and 12B in the crown adjusting unit 8 via the first power transmission means 20, and the output of the second hydraulic motor 27 is connected. The shaft is connected to the support-side turnbuckle 9a in the support adjusting unit 9 through third power transmission means 28 including two sprockets and a chain (not shown).

  As shown in FIG. 6, the first hydraulic motor 26 and the second hydraulic motor 27 are connected in parallel, and the suction ports 26 a and 27 a connected in parallel serve as a hydraulic pressure source via a variable throttle valve 29. The hydraulic pump 30 is in communication. Both the discharge ports 26 b and 27 b of the first hydraulic motor 26 and the second hydraulic motor 27 are connected in common and communicated with the tank 31.

  Then, the first hydraulic motor 26 and the second hydraulic motor 27 are simultaneously operated by the hydraulic pump 30, and the span side turn buckles 12A and 12B and the support side turn buckle 9a are simultaneously driven. The center support length is adjusted at the same time.

  At this time, the first hydraulic motor 26 and the second hydraulic motor 27 are driven in parallel by the hydraulic pump 30 to output motor outputs corresponding to the loads on the crown mechanism side and the support mechanism side, respectively. Thus, the center support length is appropriately adjusted appropriately to appropriately adjust the required crown amount, and the crown amount is adjusted very smoothly.

  The present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the screed adjustment mechanism in the road pavement machine which concerns on Example 1 of this invention, (a) is a top view, (b) is the figure which looked at figure (a) from the rear side. The expanded schematic sectional drawing which follows the XX line in FIG.1 (b). The figure which shows the relationship between the span side turnbuckle adjustment allowance in the said Example 1, and center support length. The figure which shows the relationship between the adjustment angle in the said Example 1, and the adjustment margin of a center support adjustment margin and the span side turnbuckle adjustment margin. It is a schematic block diagram of Example 2 of this invention, (a) is a top view, (b) is the figure which looked at figure (a) from the rear side. The hydraulic circuit diagram which shows the connection relation of the 1st hydraulic motor in the said Example 2, and a 2nd hydraulic motor. The side view of the conventional crawler traveling type road pavement machine. The schematic block diagram which shows the structure of the left-right screed and each support in the said prior art example. The enlarged plan view which shows the detailed structure of the crown adjustment part in the said FIG. The front view of the right-and-left screed for demonstrating crown amount.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Road pavement machine 2 Machine main body 3 Hopper 4 Screed 4A Main screed 4B Extension screed 5 Screed center pin 6A Center support 6a-6c Support 7 Support pin 8 Crown adjustment part 9 Support adjustment part 9a Support side turnbuckle (length variable means) )
10a, 10b Crown pin 11a, 11b Bracket 12A, 12B Span-side turnbuckle (span variable means)
12a, 12b Turnbuckle shaft 13 Ratchet trench 14a, 14b Sprocket 15 Chain 16 Actuator 17 Actuator sprocket 18 Span side sprocket 19 Chain 20 First power transmission means 21 Span side sprocket 22 Support side sprocket 23 Chain 24 Second power transmission means 25 internal power transmission means 26 first hydraulic motor 26
27 Second hydraulic motor 28 Third power transmission means 29 Variable throttle valve 30 Hydraulic pump (hydraulic power source)
31 tanks

Claims (5)

The length of the center adjuster provided between the left and right screeds, and the crown adjusting portion for adjusting the crown amount of the left and right screeds by changing the upper spacing distance between the left and right screeds by the span variable means. A screed adjustment mechanism in a road pavement machine comprising a variable adjustment means and a support adjustment part that adjusts the length of the center support by the length variable means according to a crown adjustment amount by the crown adjustment part,
A single actuator is connected to the span variable means and the length variable means via power transmission means, respectively, and the crown amount adjustment and the center support length adjustment are performed by the driving force of the single actuator. A screed adjustment mechanism in a road paving machine, wherein the screed adjustment mechanism is configured to be performed simultaneously.   The screed adjusting mechanism in a road pavement machine according to claim 1, wherein the actuator is either a hydraulic motor or an electric motor.   The span variable means is a span-side turnbuckle, and the power transmission means for connecting the span-side turnbuckle and the single actuator includes: a span-side sprocket on a turnbuckle shaft in the span-side turnbuckle; The actuator sprocket on the output shaft of the actuator, and the span-side sprocket and a chain spanned between the actuator sprocket. The length varying means is a support-side turnbuckle, and the support-side turnbuckle The power transmission means for connecting between the actuator and the single actuator includes: a support-side sprocket on a turnbuckle shaft in the support-side turnbuckle; an actuator sprocket on an output shaft in the actuator; Port side sprocket and screed adjusting mechanism in road paving machine according to claim 1, wherein that it is composed of a multiplying passed chain between the actuator sprockets.   An error occurring in the adjustment margin of the center support length due to driving of the span varying means and the length varying means by the single actuator is determined by the gear ratio between the span side sprocket and the support side sprocket or the span. 4. The screed adjustment mechanism in a road pavement machine according to claim 1, wherein the screed adjustment mechanism is corrected by at least one of a screw pitch difference between a side turn buckle and the support side turn buckle. The length of the center adjuster provided between the left and right screeds, and the crown adjusting portion for adjusting the crown amount of the left and right screeds by changing the upper spacing distance between the left and right screeds by the span variable means. A screed adjustment mechanism in a road pavement machine comprising a variable adjustment means and a support adjustment part that adjusts the length of the center support by the length variable means according to a crown adjustment amount by the crown adjustment part,
A first hydraulic motor is connected to the span variable means via power transmission means, a second hydraulic motor is connected to the length variable means via other power transmission means, and the first hydraulic motor and The road paving machine, wherein the second hydraulic motor is connected to a hydraulic power source in parallel and is simultaneously operated to adjust the crown amount and the center support length at the same time. Screed adjustment mechanism.

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