Line drawing device for construction

Abstract

A line drawing device for construction, characterized in that it comprises a mold body (1) and an arm (2), a cavity being arranged within the mold body (1) and the arm (2); the cavity of the mold body (1) being suitable for loading line drawing materials; the arm (2) being connected to the mold body (1); the cavity of the mold body (1) communicating with the cavity of the arm (2); the arm (2) being provided with a plurality of outlet openings, and each of the plurality of outlet openings communicating with the cavity of the arm (2); and the projections of three outlet openings in the plurality of outlet openings are respectively located at three endpoints of the same regular triangle.

Description

Technical area

[0001] The present utility model relates to the field of construction equipment, in particular to a line drawing device for construction. State of the art

[0002] In construction projects such as buildings, gardens, or roads, fixed-point marking is an important step for marking the location or area of ​​various construction facilities. Traditional marking methods are mostly manual, which is not only inefficient but also difficult to accurately control the shape and size of the marking. Regular triangular points, evenly spaced points, and parallel lines are particularly difficult to draw. Inaccurate point marking leads to poor construction quality and increased rework. Summary of the utility model

[0003] The purpose of the present utility model is to provide a device for drawing lines for construction by overcoming the deficiencies of the prior art regarding the poor accuracy in drawing regular triangular points in the construction process.

[0004] The present utility model provides a line drawing device for construction, comprising a mold body and an arm, wherein a cavity is provided inside the mold body and the arm; the cavity of the mold body is suitable for loading line drawing materials; the arm is connected to the mold body; the cavity of the mold body communicates with the cavity of the arm; the arm is provided with a plurality of outlet ports, and each of the plurality of outlet ports communicates with the cavity of the arm; and the projections of three outlet ports in the plurality of outlet ports are respectively located at three endpoints of the same regular triangle.

[0005] By connecting the cavity of the mold body to the cavity of the arm, the probability of the line-drawing material being evenly distributed in the cavity of the mold body and the cavity of the arm can be improved, and the working quality of the line-drawing device can be improved. At the same time, the working efficiency of the line-drawing device can be improved by filling the line-drawing material only into the cavity of the mold body, without filling the cavity of the mold body and the cavity of the arm.The discharge port is arranged on the arm, so that the line drawing material in the cavity of the molded body can be discharged from the discharge port via the cavity of the arm, the relative position of the discharge port can be changed by moving the line drawing device or moving the arm, and then the line drawing is performed according to the needs, so that the flexibility of using the line drawing device is improved.By arranging the protrusions of three outlet ports in a plurality of outlet ports respectively at three endpoints of the same regular triangle, when the line drawing materials are discharged from the outlet ports, the three outlet ports protruding at the three endpoints of the regular triangle can protrude into the target area for line drawing, and the mark of the regular triangle can be obtained by connecting the three endpoints to improve the accuracy of drawing the mark of the regular triangle, thereby improving the construction quality and reducing the probability of rework.At the same time, by improving the accuracy of drawing the regular triangle mark, the right circle can also be drawn according to the right triangle, and the accuracy of drawing the right circle can be improved.

[0006] The molded body and / or the arm can each be designed as a hollow body, or a hollow body can be fixedly arranged inside the molded body and / or inside the arm.

[0007] The arm can be movably attached to the molded body or be firmly connected to the molded body.

[0008] The number of outlet ports is at least 3, preferably 3, and the number of outlet ports can also be set to 4 or 5, etc.

[0009] When the number of outlet ports is greater than three, the three outlet ports protruding on the three endpoints of the same regular triangle can be kept in an open state during use, and the other outlet ports are closed by means of a cover plate or a wooden plug, etc., so that the line drawing materials are discharged from the three outlet ports to draw the three endpoints of the regular triangle.

[0010] The arm comprises three arm units, one end of each of the three arm units being connected to the mold body and the other end being provided with an outlet opening.

[0011] By providing three arm units, each arm unit is provided with an outlet port, resulting in a total of three outlet ports on the arms. The protrusions are located at three endpoints of the same regular triangle, further improving the accuracy of the line drawing device for drawing the regular triangle.

[0012] The mold body is a cylinder; three of the arm units are attached to the mold body as a sleeve; three of the arm units rotate circumferentially around the mold body; the mold body is arranged with clamping parts at three evenly distributed points along the circumferential direction of the mold body; and three of the clamping parts are each suitable for clamping three of the arm units to the mold body.

[0013] The arm units can all rotate around the circumference of the mold body, so that the line-drawing device can adjust the position of each arm unit according to requirements and then adjust the distance between each outlet port to perform line-drawing work with different requirements and improve the adaptability of the device. By providing clamping parts at three evenly distributed points of the mold body along the circumferential direction of the mold body, each arm unit can be clamped to the mold body respectively. When each arm unit is clamped to the mold body, the included angle between two adjacent arm units is 60°, and the protrusions of each outlet port are respectively located at three endpoints of the same regular triangle.By this arrangement, the device can be adjusted so that the projections of each outlet port can be arranged at three endpoints of the same regular triangle according to the adjustment of the relative positions of the arm units, thereby improving the flexibility of the device.

[0014] The shaped body can also be in the form of a sphere, a cone or the like.

[0015] The arm unit is retractable and is provided with a scale line.

[0016] With this arrangement, the length of the arm unit can be adjusted by extending and retracting the arm unit according to the indication of the scale, so that the projection of each outlet port can be arranged at the end point of the same regular triangle, and regular triangles of different sizes can be drawn according to requirements.

[0017] The arm includes an additional portion, the additional portion being arranged in accordance with the arm unit; the additional portion being connected to the arm unit by a slide rail; the additional portion being movable along the length of the arm unit; the additional portion sliding to change the length according to the arm unit; and the outlet port being arranged in the additional portion.

[0018] By providing an additional section, the length of the corresponding arm unit can be adjusted according to requirements, and then the distance between each outlet port can be changed, so that the protrusion of each outlet port can be arranged at the endpoints of regular triangles of different sizes. By providing a slide rail, when the additional section slides, the friction between the arm unit and the additional section can be reduced, so that the sliding is smoother and the probability of the additional section being damaged due to friction can be reduced.

[0019] The additional section can also be connected to the arm unit via a slider or pulley.

[0020] The arm unit is also equipped with a locking element to limit the movement of the additional section.

[0021] By providing a locking member, by using the locking member to limit the movement of the additional portion when the additional portion is adjusted to the position required for the operation of the device, the probability of movement of the additional portion during the operation of the device is reduced, thereby improving the accuracy of the device.

[0022] The locking element may be a bolt and a threaded hole provided in the additional portion, or it may be provided as a hook or the like used in cooperation with each other.

[0023] The mold body is further provided with an actuating device which is connected to the cavity of the mold body in order to expel the line drawing material from the outlet opening.

[0024] By providing the actuating device such that the actuating device drives the line drawing material to be discharged from the discharge opening, the usability of the device is improved.

[0025] The actuating device is an air pump provided within the mold body and communicating with the cavity of the mold body; the air pump is provided with a support rod slidably connected to an inner wall of the air pump; the support rod is movable to compress air in the air pump; and an air pressure switch is connected to the air pump, the air pressure switch being operable to discharge air from the air pump.

[0026] By arranging the support rod slidably connected to the inner wall of the air pump, and sliding the support rod to compress air in the air pump, the support rod is integrally arranged in the air pump, so that the volume of the device is reduced and the device is convenient to carry. At the same time, the support rod and the air pump are slidably connected to each other, which reduces the friction between the support rod and the air pump and improves the convenience of the compressed air process. By equipping it with an air pressure switch, the air outlet of the air pump can be switched as needed. When it is necessary to discharge the drawing material, the air pressure switch is opened, and the compressed air in the air pump enters the cavity of the mold body to discharge the drawing material from the outlet.When the air pressure switch is closed, the air flow in the air pump to the mold cavity is blocked. This arrangement allows the air pressure switch to be activated as needed to expel the drawing material from the outlet or retain it in the mold cavity, thus improving the flexibility of the device.

[0027] The actuating device can also be designed as a hydraulic pump or electric air pump or similar.

[0028] The molded body is also equipped with a handle.

[0029] The movement and carrying of the device is facilitated by the provision of the handle, which may be arranged integrally with the molded body or may be removably connected thereto.

[0030] The molded body is further provided with an outlet opening which is connected to the cavity of the molded body.

[0031] By providing the outlet port in the mold body, other marks can be drawn according to actual needs, which improves the applicability of the device.

[0032] Compared to the prior art, the present utility model has the following advantages.

[0033] 1. The present utility model provides a device for drawing lines for construction. By providing a mold body and an arm, a cavity is provided within the mold body and the arm; the cavity of the mold body is suitable for loading line drawing materials; the arm is connected to the mold body; the cavity of the mold body communicates with the cavity of the arm; the arm is provided with a plurality of outlet ports, and each of the plurality of outlet ports communicates with the cavity of the arm; and the projections of three outlet ports in the plurality of outlet ports are respectively arranged at three endpoints of the same regular triangle to improve the accuracy of drawing a mark of the regular triangle, thereby improving construction quality and reducing the likelihood of rework. Brief description of the drawings Fig. 1 is a main schematic view of a line drawing device for construction according to Embodiment 1 of the present utility model. Fig. 2 is a schematic plan view of a line pulling device for construction according to Embodiment 2 of the present utility model. Fig. 3 is a schematic bottom view showing a first operating state of the line pulling device for construction according to Embodiment 2 of the present utility model. Fig. 4 is a schematic bottom view illustrating a second operating state of the line pulling device for construction according to Embodiment 2 of the present utility model. Fig. 5 is a schematic bottom view showing a third operating state of the line pulling device for construction according to Embodiment 2 of the present utility model. Fig. 6 is a schematic bottom view showing a fourth operating state of the line pulling device for construction according to Embodiment 2 of the present utility model. Reference symbol:

[0034] 1-Molded body, 11-Retaining rod, 12-Air pressure switch, 13-Handle, 2-Arm, 21-Additional section, 22-Locking element, 3-First one-way valve, 4-Second one-way valve, 5-Soft plug, 6-Outlet port. Detailed description

[0035] The present utility model will be described in more detail below with reference to specific embodiments. However, it should not be understood that the scope of the above-described subject matter of the present utility model is limited to the following examples, and it is intended that the present utility model falls within the scope of the present utility model.

[0036] In the description of specific embodiments of the present utility model, the terms "top", "bottom", "left", "right", "center", "inside", "outside" and the like, unless otherwise stated, refer to any orientation or positional relationship and are to be understood as expressions based on the orientation or positional relationship shown in the drawings or on the orientation or positional relationship in which the product / apparatus / device of the present utility model is commonly used.These terms of orientation or positional relationship are merely intended to facilitate the description of aspects of the present utility model or to simplify the description of certain embodiments for those skilled in the art to quickly understand aspects, and do not imply that a particular device / part / element must have a particular orientation or be designed and operated in a particular positional relationship, and therefore should not be construed as a limitation of the present utility model.

[0037] Furthermore, the presence of the terms "horizontal," "vertical," "overhanging," "parallel," and the like does not imply that the respective device / component / element must be absolutely horizontal or vertical, or overhanging or parallel, but may also be slightly inclined or offset. While "horizontal" simply means that its direction is more horizontal than "vertical," this does not mean that the structure must be completely horizontal, but may be slightly inclined.

[0038] Alternatively, it can simply be assumed that the respective means / parts / elements arranged in a "horizontal," "vertical," "overhanging," "parallel" direction, etc., can be arranged with an error / deviation of ± 10%, more preferably within ± 8%, more preferably within ± 6%, more preferably within ± 5%, more preferably within ± 4% relative to the respective direction. As long as the corresponding device / part / element lies within the error / deviation range, its function can still be fulfilled in the solution of the present utility model.

[0039] Furthermore, the terms “first,” “second,” “third,” and similar terms in such sentences are used solely to distinguish between descriptions of the same or similar elements and are not to be understood as emphasizing or implying a relative importance of the respective elements.

[0040] Furthermore, in the description of the embodiments of the present utility model, "some," "a plurality," and "plural" refer to at least two. There may be 2, 3, 4, 5, 6, 7, 8, 9, etc., and there may be more than 9.

[0041] Furthermore, when the terms "provide," "attach," "connect," "connect," "provide," "lay," and "arrange" appear in the description of the technical solution of the present utility model, they are to be understood in the broadest sense, unless expressly stated / restricted / limited otherwise. For example, the connection may be a fixed connection, a detachable connection, or an integral connection, and it may involve a connection means commonly used in technology, such as welding, riveting, screwing, bolting, etc. The connection may be mechanical, electrical, or communication. The connection may be direct or indirect via an intermediate medium, and the two elements may be connected to each other. Embodiment 1

[0042] As in Fig. 1, a line drawing device comprises a mold body 1 and an arm 2. A cavity is provided within the mold body 1 and the arm 2. The cavity of the mold body 1 is provided for filling line drawing materials. The arm 2 is connected to the mold body 1. The cavity of the mold body 1 can communicate with the cavity of the arm 2. The arm 2 is provided with a plurality of outlet openings 6. The plurality of outlet openings 6 all communicate with the cavity of the arm 2. The projections of three outlet openings 6 in the plurality of outlet openings 6 are respectively located at three endpoints of the same regular triangle.

[0043] By connecting the cavity of the mold body 1 to the cavity of the arm 2, the probability that the line-drawing material is evenly distributed in the cavity of the mold body 1 and the cavity of the arm 2 can be improved, and the working quality of the line-drawing device can be improved. At the same time, the working efficiency of the line-drawing device can be improved by filling the line-drawing material only into the cavity of the mold body 1, without filling the cavity of the mold body 1 and the cavity of the arm 2 respectively.By providing an outlet port 6 on the arm 2, the line drawing material in the cavity of the molded body 1 can be discharged from the outlet port 6 via the cavity of the arm 2, the relative position of the outlet port 6 can be changed by moving the line drawing device or moving the arm 2, and then the line drawing is performed as needed, so that the flexibility of using the line drawing device is improved.By arranging the protrusions of three outlet ports 6 in a plurality of outlet ports 6 respectively at three endpoints of the same regular triangle, when the line drawing material is discharged from the outlet ports 6, the three outlet ports 6 protruding at the three endpoints of the same regular triangle can protrude the three endpoints of the regular triangle into the target area for line drawing, and the mark of the regular triangle can be obtained by connecting the three endpoints to improve the degree of accuracy in drawing the mark of the regular triangle, thereby improving the construction quality and reducing the probability of rework.

[0044] The mold body 1 and the arm 2 are both hollow, the arm 2 is fixedly connected to the mold body 1, and the number of outlet openings 6 is three.

[0045] The arm 2 consists of three arm units. One end of each of the three arm units is connected to the mold body 1, and the other end is provided with an outlet opening 6.

[0046] By providing three arm units, each arm unit is provided with an outlet opening 6, so that the outlet openings 6 on the arm 2 are three in total, and the projections of the outlet openings 6 are respectively located at three end points of the same regular triangle, thereby further improving the accuracy of the line drawing device for drawing a regular triangle.

[0047] The arm unit is retractable and is provided with a scale line.

[0048] With this arrangement, the length of the arm unit can be adjusted by extending and retracting the arm unit according to the indication of the scale, so that the projection of each outlet port 6 can be arranged at the end point of the same regular triangle, and regular triangles of different sizes can be drawn according to requirements.

[0049] The arm 2 includes an additional section 21 provided in correspondence with the arm unit. The additional section 21 is connected to the arm unit by a slide rail. The additional section 21 is movable along the length of the arm unit. The additional section 21 slides to change the length according to the arm unit. The outlet opening 6 is arranged in the additional section 21.

[0050] By providing the additional section 21, the length of the corresponding arm unit can be adjusted according to requirements, and then the distance between the exhaust ports 6 can be changed, so that the projection of the exhaust ports 6 can be arranged at the endpoints of regular triangles of different sizes. By providing the slide rail, when the additional section 21 slides, the friction between the arm unit and the additional section 21 can be reduced, so that the sliding is smoother, and the probability of the additional section 21 being damaged due to friction can be reduced. The arm unit is further provided with a locking element 22 for limiting the movement of the additional section 21.

[0051] By providing the locking member 22, by using the locking member 22 to limit the movement of the additional portion 21 when the additional portion 21 is adjusted to the position required for the operation of the device, the probability of movement of the additional portion 21 during the operation of the device is reduced, thereby improving the accuracy of the device.

[0052] The locking element 22 is a locking block capable of clamping the additional section 21 together with the arm unit corresponding to the additional section 21.

[0053] The mold body 1 is further provided with an actuating device which is connected to the cavity of the mold body 1 in order to expel the line drawing material from the outlet opening.

[0054] By making the actuating device suitable for driving the drawing material to be discharged from the outlet opening, the user-friendliness of the device is improved.

[0055] The drive device is an air pump arranged inside the molded body 1 and communicating with the cavity of the molded body 1. The air pump comprises an air inlet tank and an air storage tank. The air inlet tank communicates with the air storage tank via a first one-way valve 3, and the air storage tank communicates with the cavity of the molded body 1 via a second one-way valve 4. The first one-way valve 3 is adapted to limit the gas movement from the air storage tank to the air inlet tank. The second one-way valve 4 is adapted to limit the gas movement from the cavity of the molded body 1 to the air storage tank. The air pump is provided with a support rod 11 and an air pressure switch 12, and the support rod 11 is provided with a soft plug 5. The support rod 11 is slidably connected to the inner wall of the air pump via the soft plug 5.By moving the support rod 11, air can be compressed into the air pump, and the air pressure switch 12 is connected to the air pump, and by operating the air pressure switch 12, air can be released from the air pump.

[0056] By arranging the support rod 11 slidably connected to the inner wall of the air pump and sliding the support rod 11 to compress air into the air inlet tank, the support rod 11 is integrally arranged in the air pump, thereby reducing the volume of the device and making the device easy to carry. At the same time, the support rod 11 is slidably connected to the air pump, which reduces friction between the support rod 11 and the air pump and improves the convenience of the compressed air process. By providing the first one-way valve 3, the gas can flow from the gas inlet tank to the gas storage tank, reducing the likelihood of gas backflow and improving the effect of compressing the gas in the gas storage tank.By providing the second one-way valve 4, the gas can flow from the gas storage container into the cavity of the mold body 1, thereby reducing the probability of backflow of the gas and reducing the probability of the drawing material entering the gas storage container, thereby improving the service life of the air pump. By providing the air pressure switch 12 connected to the second one-way valve 4, the second one-way valve 4 can be switched and operated as needed. When the line drawing material needs to be dispensed and the air pressure switch 12 is open, the compressed air in the air pump enters the cavity of the mold body 1 and drives the drawing material to be dispensed from the dispensing port. When the air pressure switch 12 is closed, the inflow of air in the air pump to the cavity of the mold body 1 is blocked.With this arrangement, the air pressure switch 12 can be operated as needed so that the line drawing materials are discharged from the discharge port or remain in the cavity of the mold body 1, thereby improving the flexibility of the device.

[0057] The molded body 1 is also provided with a handle 13.

[0058] The movement and carrying of the device is facilitated by the presence of the handle 13, which can be provided integrally with the molded body 1 or can be removably connected thereto. Embodiment 2

[0059] As in the Fig. 2-6, the present embodiment differs from Embodiment 1 in that the mold body 1 is a cylinder; three of the arm units are pushed onto the mold body 1; three of the arm units rotate circumferentially around the mold body 1; the mold body 1 is provided with clamping parts at three evenly distributed points along the circumferential direction of the mold body 1; and three of the clamping parts are each suitable for clamping three of the arm units to the mold body 1.

[0060] The arm units can all rotate around the circumference of the die body 1, so that the line-drawing device can adjust the position of each arm unit according to requirements and then adjust the distance between each outlet port 6 to perform line-drawing work with different requirements and improve the adaptability of the device. By providing clamping parts at three evenly distributed points of the die body 1 along the circumferential direction of the die body 1, each arm unit can be clamped to the die body 1, respectively. When each arm unit is clamped to the die body 1, the included angle between two adjacent arm units is 60°, and the protrusions of each outlet port 6 are respectively located at three endpoints of the same regular triangle.By this arrangement, the device can be adjusted so that the projections of each outlet port 6 can be arranged at three end points of the same regular triangle according to the adjustment of the relative positions of the arm units, thereby improving the flexibility of the device.

[0061] The molded body 1 is further provided with an outlet opening 6 which is connected to the cavity of the molded body 1.

[0062] By arranging the outlet opening 6 in the mold body 1, other markings can be drawn according to actual needs, thereby improving the applicability of the device.

[0063] As in Fig. As shown in Figure 3, in the first operating state, two of the arm units in arm 2 can be moved to overlap along the axial direction of the die body 1, the other arm unit can be moved to form an angle of 180° with the other two arm units, and the additional section 21 is extended to the outermost position. In operation, the air pump is actuated to discharge the line drawing material from the outlet port of arm 2 and the outlet port of the die body 1. At the same time, the die body 1 is moved so that three mutually parallel lines or three equally spaced dots can be drawn.

[0064] As in Fig. As shown in Figure 4, in the second operating state, the three arms 2 can be moved so that they overlap in the axial direction of the die body 1, and the additional section 21 is shortened to a minimum. During operation, the air pump is actuated to discharge the drawing material from the outlet port of the arm 2 and the outlet port of the die body 1. At the same time, the die body 1 is moved so that two parallel lines can be drawn.

[0065] As in Fig. As shown in Figure 5, in the third operating state, the three arms 2 can be moved to overlap in the axial direction of the die body 1, and a part of the additional portion 21 protrudes from the arms 2. During operation, the air pump is actuated to eject the line-drawing material from the outlet port of the arms 2 and the outlet port of the die body 1. At the same time, the die body 1 is moved, and two parallel lines can be drawn.

[0066] As in Fig. As shown in Figure 6, in the fourth operating state, the three arms 2 can be moved to overlap axially along the die body 1, and the additional section 21 is extended to the outermost position. During operation, the air pump is actuated to discharge the line-drawing material from the outlet port of the arm 2 and the outlet port of the die body 1. At the same time, the die body 1 is moved so that two parallel lines can be drawn.

[0067] The above description merely represents preferred embodiments of the utility model and is not intended to limit the utility model. All modifications, equivalents, and improvements that are consistent with the spirit and principles of the utility model are intended to be included within the scope of the utility model.

[0068] The present utility model relates to the field of building construction equipment, particularly to a line-drawing device for construction. The present utility model comprises a mold body and an arm, wherein a cavity is disposed within the mold body and the arm; the cavity of the mold body is suitable for loading line-drawing materials; the arm is connected to the mold body; the cavity of the mold body communicates with the cavity of the arm; the arm is provided with a plurality of outlet ports, and each of the plurality of outlet ports communicates with the cavity of the arm; and the projections of three outlet ports in the plurality of outlet ports are respectively arranged at three endpoints of the same regular triangle to improve the accuracy of drawing a mark of the regular triangle, thereby improving construction quality and reducing the likelihood of rework.

Claims

[1] Line drawing device for construction, characterized by , comprising a mold body (1) and an arm (2), wherein a cavity is arranged within the mold body (1) and the arm (2); the cavity of the mold body (1) is suitable for loading line drawing materials; the arm (2) is connected to the mold body (1); the cavity of the mold body (1) communicates with the cavity of the arm (2); the arm (2) is provided with a plurality of outlet openings, and each of the plurality of outlet openings communicates with the cavity of the arm (2); and the projections of three outlet openings in the plurality of outlet openings are each located at three endpoints of the same regular triangle. [2] Line drawing device for construction according to claim 1, characterized bythat the arm (2) comprises three arm units, one end of each of the three arm units being connected to the mold body (1), and the other end thereof being provided with an outlet opening. [3] Line drawing device for construction according to claim 2, characterized by that the molded body (1) is a cylinder; three of the arm units are pushed onto the molded body (1); three of the arm units rotate in the circumferential direction around the molded body (1); the molded body (1) is arranged with clamping parts at three evenly distributed points along the circumferential direction of the molded body (1); and three of the clamping parts are each suitable for clamping three of the arm units to the molded body (1). [4] Line drawing device for construction according to claim 2 or 3, characterized by that the arm unit is retractable, wherein the arm unit is arranged with a scale line. [5] Line drawing device for construction according to claim 4, characterized bythat the arm (2) comprises an additional section (21), wherein the additional section (21) is arranged in accordance with the arm unit; the additional section (21) is connected to the arm unit by a slide rail; the additional section (21) is movable along the length of the arm unit; the additional section (21) slides to change the length according to the arm unit; and the outlet opening is arranged in the additional section (21). [6] Line drawing device for construction according to claim 5, characterized by that the arm unit is further provided with a locking element (22) for limiting the movement of the additional section (21). [7] Line drawing device for construction according to claim 4, characterized bythat the mold body (1) is further arranged with an actuating device which is in communication with the cavity of the mold body (1) in order to expel the line drawing material from the outlet opening. [8] Line drawing device for construction according to claim 4, characterized by that the actuating device is an air pump which is arranged inside the molded body (1) and communicates with the cavity of the molded body (1); the air pump is provided with a support rod (11) which is slidably connected to an inner wall of the air pump; the support rod (11) is movable to compress air into the air pump; and an air pressure switch (12) is connected to the air pump, the air pressure switch (12) being operable to discharge air from the air pump. [9] Line drawing device for construction according to claim 4, characterized by that the shaped body (1) is further provided with a handle (13). [10] Line drawing device for construction according to claim 4, characterized by that the shaped body (1) is further provided with an outlet opening which is in communication with the cavity of the shaped body (1).

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