The Improved Guide Bar Structure for Shading Screen Curtain Device in Agricultural Greenhouses

Abstract

The tow bar structure has been improved to allow for stable operation of shading screen curtains installed longitudinally within a greenhouse, and to enable easy and convenient replacement by pulling them after a certain period of use. The focus of this development was on providing an improved tow bar structure for agricultural greenhouse shading screen curtains that maintains uniform traction, enhances stability by preventing unilateral sagging during opening and closing, and allows for efficient replacement work. In a horizontal curtain device for a vinyl greenhouse, a towing bar or a towing bar is optionally configured to stably guide and pull the screen curtain in the longitudinal direction, allow for easy replacement even after a certain period of use, and ensure pulling stability while maintaining a uniform pulling force of the screen curtain. The present invention, as described above, has the effect of reducing costs and time during the construction process by being easy and quick to install. It also improves the method of unfolding or taking down the existing tent to allow for easy and convenient replacement by pulling it in one direction, and provides a towing bar that allows for easy replacement in the longitudinal direction during replacement, thereby offering the advantage of stable operation.

Description

Technology Field

[0001] The present invention relates to an improved towing bar structure for shading screen curtains used to regulate the internal environment of agricultural greenhouses. More specifically, the structure of the towing bar is improved to allow for easy and convenient replacement by pulling the shading screen curtain, which is installed longitudinally with a certain width inside the greenhouse, even after stable operation and use for a certain period. The invention focuses on providing an improved towing bar structure for agricultural greenhouse shading screen curtains that maintains uniform traction force, enhances stability by preventing unilateral sagging that may occur during the opening and closing process, and enables efficient replacement work. Background Technology

[0002] Typically, vinyl greenhouses are installed and used to maintain a constant temperature suitable for crop growth, enabling the cultivation of various crops for early shipment or the growing of specialty crops regardless of the season.

[0003] When cultivating crops or flowers forcibly inside such a greenhouse, horizontal non-woven fabric is installed on the ceiling to maintain nighttime warmth during the winter and allow sunlight to pass through during the day, while conversely, in the summer, a shade net is installed instead of the non-woven fabric to block sunlight, and the temperature is controlled by covering it during the day and removing it at night.

[0004] Traditionally, non-woven fabrics were primarily used as such thermal covers; however, recently, screen fabrics have been developed that are lighter while maintaining the same thermal insulation and light-blocking functions, replacing existing non-woven fabrics. These screen fabrics are widely used because their lightweight structure reduces the load during opening and closing, and their improved durability provides stable performance even during long-term use.

[0005] Conventional thermal covers and shading net opening and closing devices, which operate by using a tugboat and a winding roller to pull or unfold non-woven fabric or shading net in a zigzag pattern, had problems such as the fabric getting twisted or tension being applied unevenly during the opening and closing process of the screen curtain, resulting in poor operation and requiring a lot of manpower and time when replacing the fabric.

[0006] Accordingly, the existing towing method has been improved to provide a structure in which the screen fabric is wound on one side and pulled by a tow bar in the longitudinal direction, allowing for easy replacement after a certain period. This design facilitates the easy separation and connection of the tow bar even when replacing the screen fabric, thereby significantly improving maintenance efficiency.

[0008] Various forms of prior art related to the improved structure of a towing bar for agricultural vinyl greenhouse shading screen curtains are known.

[0010] For example, in Korean Registered Patent Publication No. 10-2334445 (Publication Date: Dec. 03, 2021), “a multi-layer opening / closing device is provided, comprising vertical support posts (101) fixedly installed on both sides of the ground (B), and horizontal support posts (102)(103) provided on the inner upper side of the vertical support posts (101), wherein a thermal insulation cover in the form of a non-woven fabric is moved horizontally left and right between the two horizontal support posts (102)(103) to enable opening and closing, wherein a multi-layer opening / closing device (A) is configured such that the thermal insulation cover (C)(C-1) installed between the two horizontal support posts (102)(103) is double-layered to enable opening and closing, and wherein the multi-layer opening / closing device (A) is provided by a wire fixing means (4) on the outer surface of each horizontal support post (102)(103) Support wires (201)(202) are provided to maintain a constant tension horizontally, and several or more support wires (201)(202) are provided at regular intervals on the front and rear sides. A movement direction changing roller (6) equipped with one or more multi-rollers (651) is provided to be fixedly engaged on the outer surface of the horizontal support member (103). A direction changing roller (6-1) equipped with a rotating roller (651) is provided to be fixedly engaged symmetrically on the front and rear sides on the outer surface of the horizontal support member (102) opposite the changing roller (6). A traction wire (3)(3-1) is provided to be rotated while being horizontally guided on the changing roller (6) and the direction changing roller (6-1). The traction wire (3)(3-1) is provided to be rotated by the forward and reverse rotational force of a power transmission means (9) fixedly installed on the vertical support member (101). In addition to the above, the outer end of the thermal cover (C)(C-1) is secured to the outer surface of each of the above transverse support members (102)(103) by a cover fixing means (5), and the inner end of the thermal cover (C)(C-1) is secured to the traction wire (3)(3-1) by a moving clamp means (7), and according to the rotational direction of the traction wire (3)(3-1), the thermal cover (C) is seated on the upper surface of the support wire (201)(202) and guided to open and close.The above-mentioned opposite side thermal cover (C-1) is configured to be movable and open / closed while securing a space (S) that spreads out in multiple directions by being seated on the upper surface of the above-mentioned traction wire (3)(3-1); the above-mentioned wire fixing means (4) is provided with a fixing ring (420) with one side open to be hooked and fixed along the outer surface of each transverse support member (102)(103), wherein the fixing ring (420) is provided in a “⊃” shape with a certain spacing in the front and rear directions, and a connecting block (410)(410-1) is configured on one side of the fixing ring (420) to which the above-mentioned support wire (201)(202) is fastened and fixed, and the above-mentioned connecting block (410-1) is provided with an open groove (469) with one side open in the center, and a rotating shaft rod (462) that is inserted and rotated in the above-mentioned open groove (469), and the of the above-mentioned rotating shaft rod (462). The outer surface is provided to be wound with support wires (201)(202), and a ratchet (461) is provided on one side of the outer side of the rotating shaft (462), and is provided to be engaged with a catch (463) hinged to one side on the same line as the ratchet (461), and the catch (463) is configured such that one side of the elastic spring (464) is caught and the other side of the elastic spring (464) is inserted into a fixing groove (410-2) so that it springs out by tension, and the power transmission means (9) is configured such that the traction wire (3)(3-1) rotating through each switching roller (6), direction switching roller (6-1), and switching roller (6) is fastened and fixed by a fastening knuckle (90) having a circular connecting groove (92) with a bearing (91) inserted on one side of the vertical support member (101). A rotating pipe (910) is provided at the center of the bearing (91) to rotate axially, and a traction wire (3)(3-1) is provided to be wound in opposite directions on the outer surface of the rotating pipe (910), and a protruding square connecting pin (955) is provided at one end of the rotating pipe (910), and a rotating gear (951) is provided on the opposite outer surface to be chain-connected to a driving gear (M-1) of a reduction motor (M) that rotates in forward and reverse directions by receiving external power.The above-mentioned rotating pipe (910) is configured such that one or more expansion connecting pipes (910-1) of partitioned sizes are connected and fixed to rotate with each other, and the expansion connecting pipe (910-1) is provided with a connecting groove (971) on one side that is inserted and fixed in correspondence with the square connecting pin (955), and on the opposite side, a protruding square connecting pin (955-1) is provided, and a fixing screw (972) is formed on the outer surface of the connecting groove (971) so that the connecting groove (971) and the square connecting pin (955) (955-1) do not detach from each other while connected, and the above-mentioned cover fixing means (5) is configured such that the outer end of the thermal insulation cover (C) (C-1) wraps along the outer surface of each horizontal support member (102) (103), and on the outer surface of the wrapped thermal insulation cover (C) (C-1), one side is open A horizontal type for a vinyl greenhouse is characterized by being configured to fasten and secure one or more clamp bands (510), and having a pipe fastening hook (521) with one side open to be hooked and secured along the outer surface of each horizontal support post (102)(103), wherein the pipe fastening hook (521) is provided in a “⊃” shape with a certain spacing in the front and rear directions, and having a longitudinally expanding horizontal bar (522) provided at the center of one side of the pipe fastening hook (521), and having one or more protruding bars (523) protruding from one side, and having a loop-shaped hook (524) provided at the outer end of the protruding bar (523), and having a vertically protruding vertical support piece (535) provided at the outer end of the protruding bar (523), and having an inwardly bent anti-detachment piece (536) provided at the upper end of the vertical support piece (535). There is a “multi-layer thermal cover opening and closing device,” and

[0012] In addition, Korean Registered Patent Publication No. 10-1455113 (Publication Date: Oct. 28, 2014) describes an opening and closing system for a thermal insulation curtain for a vinyl greenhouse comprising: a vertical frame (1) in the shape of "∩" installed vertically at intervals; an upper perimeter frame (2) fixed in the shape of "□" above the vertical portion of the vertical frame (1) to support the frame formed by the vertical frame (1); a horizontal frame (3) arranged and fixed parallel to the upper perimeter frame (2) at intervals; and a thermal insulation curtain (4) that is opened and closed while being wound along the upper part of the horizontal frame (3) in a transverse direction; wherein the system comprises: a curtain winding motor (11a) that rotates a transverse bar (11b) on which the thermal insulation curtain (4) is wound in forward and reverse directions, and an opening and closing path (11c) that provides a straight reciprocating transverse path in conjunction with the rotational force of the curtain winding motor (11a). A “thermal curtain drive unit (11) configured to include a guide rod (11e) that is provided parallel to the center adjacent to the above-mentioned opening / closing path (11c) and supports and guides the transverse of a plate (11d) to which a curtain winding motor (11a) is fixed; a contact wire drive unit (12) configured to include a tension rod (12a) that is provided parallel to the center adjacent to a horizontal frame (2-1) to which one end of the thermal curtain (4) is fixed, and which unwinds or winds a contact wire (12c) while rotating by a tension motor (12b); and a control unit (13) that outputs and controls the operation signals of the thermal curtain drive unit (11) and the contact wire drive unit (12) according to a pre-set program signal or a manual operation signal.

[0014] In addition, Korean Registered Patent Publication No. 10-2709249 (Publication Date: September 25, 2024) describes a “horizontal curtain device for a greenhouse, comprising a frame of a greenhouse, a horizontal curtain installed on the frame to cover crops of the greenhouse, a curtain frame installed on the frame to support the horizontal curtain, and a guide shaft inserted into the curtain frame and supporting the end of the horizontal curtain, wherein both ends of the horizontal curtain are wound to form a guide insertion hole into which the guide shaft is inserted, and wherein the guide shaft further comprises a guide stopper inserted into the curtain frame to prevent movement of the guide shaft, and a guide connector formed with a certain unit length to connect the guide shaft.”

[0016] Additionally, Korean Published Patent Application No. 10-2025-0094172 (Publication Date: June 25, 2025) describes a “plastic greenhouse house characterized by comprising: a steel pipe section (10) having a partition piece (12) formed in the center of the steel pipe (11) and fastening pieces (13) protruding on both sides of the inner surface of the steel pipe (11); a fixing section (20) having a contact piece (21) formed in the outer center of the steel pipe (11) of the steel pipe section (10) so as to extend from the partition piece (12), a fixing pipe (23) formed on both sides of the contact piece (21) so as to insert a vinyl (V) and a fixing plate spring (22), and an insertion hole (24) formed on the outer surface of the fixing pipe (23); and a separating section (30) having a separating piece (31) formed protruding from the contact piece (21) in the outer center of the fixing pipe (23) of the fixing section (20). The "leaf spring fixed frame" is becoming known.

[0018] As mentioned above, various types of improved structures for agricultural vinyl greenhouse shading screen curtain towing bars are known and in use, but

[0020] In the aforementioned registered patent publication No. 10-2334445, the conventional multi-layer opening and closing device for a horizontal thermal insulation cover for a vinyl greenhouse is configured to open and close the thermal insulation cover by complexly combining various parts such as multiple rollers, direction changing rollers, traction wires, wire fixing means, and cover fixing means between vertical support posts and horizontal support posts, but

[0021] Among these components, the movable gripping mechanism is designed for conventional non-woven fabrics and presents a problem in that it is unsuitable for the lightweight screen fabrics currently in use. Furthermore, when the thermal cover is unfolded or rolled up, the cover is pulled over by movable gripping mechanisms installed at regular intervals according to the direction of operation, resulting in inconsistent traction force and the problem of incurring significant costs and time when replacing the cover. In addition, the high temperature and humidity environment inside the greenhouse causes components to corrode easily, making smooth operation difficult. Moreover, if the fastening structure between parts is not precise, jamming or malfunctions may occur during the opening and closing process, leading to increased installation and maintenance time.

[0023] Furthermore, in Registered Patent Publication No. 10-1455113, the opening and closing system for a thermal insulation curtain for a vinyl greenhouse is configured to open and close the curtain by combining various components such as a vertical frame, an upper rim frame, a horizontal frame, a winding motor, a tension motor, and a close-contact wire drive unit. Through this, the purpose is to provide excellent thermal insulation even at a thin thickness by configuring the thermal insulation curtain with an aluminum reflective insulation material in which aluminum is laminated onto the surface of the fabric, and to improve storage properties by reducing the diameter when wound, but

[0024] Since the thermal curtain is opened and closed only by fixing it to one side and rolling it up from the other, there are structural issues such as increased bulk and prolonged opening / closing times. Furthermore, this roll-type structure is unsuitable for recently used lightweight screen fabrics, limiting its application. Additionally, if installed in separate zones to shorten opening / closing times, separate installation is required for each structure, leading to increased installation costs. Moreover, the addition of connecting structures for each zone increases the installation load, posing a risk of safety accidents.

[0026] In addition, Korean Registered Patent Publication No. 10-2709249 aims to provide an opening and closing system for a thermal insulation curtain for a vinyl greenhouse that is installed in the upper part of a greenhouse for facility cultivation to perform thermal insulation and shading functions, specifically by ensuring that when the thermal insulation curtain is opened, it is rolled into a slim state (small diameter), firmly pressing the unfolded thermal insulation curtain to prevent it from fluttering in the wind, simplifying the configuration or structure related to the opening and closing drive of the thermal insulation curtain, and automatically opening and closing according to light intensity, temperature, and humidity.

[0027] Although it has a structure in which horizontal curtains are wound onto movable curtain frames from both sides and inserted into guide shafts, there is a problem in that it is difficult to guarantee robust durability, and there are issues such as the horizontal curtains becoming detached due to spreading during long-term use.

[0029] In addition, Korean Published Patent Application No. 10-2025-0094172 aims to provide a leaf spring fixed vertical frame for a vinyl greenhouse by forming a fixing steel pipe in the vertical frame forming a tunnel-type or roof-type vinyl greenhouse and fixing the vinyl to each vertical frame by means of fastening a leaf spring and a pressing plate, thereby facilitating construction, improving the fixing strength of the vinyl greenhouse to increase durability, making it easy to install front and back finishing and entrance doors of the vinyl greenhouse, as well as facilitating the additional installation of many functional components such as sprinklers or awnings.

[0030] However, since this structure is designed only as a fixed type, it presents a problem in that it is difficult to apply to screen fabrics that require replacement as a mobile type. Additionally, due to its complex structure, while it is suitable for fixed support types, it has structural limitations that make it difficult to use for movement and replacement operations, and improvements are currently required. Prior art literature

[0031] · Korean Registered Patent Publication No. 10-2334445 (Publication Date: Dec. 03, 2021) · Korean Registered Patent Publication No. 10-1455113 (Publication Date: Oct. 28, 2014) · Korean Registered Patent Publication No. 10-2709249 (Publication Date: Sep. 25, 2024) · Korean Published Patent Publication No. 10-2025-0094172 (Publication Date: June 25, 2025)

[0032] doesn't exist The problem to be solved

[0033] Accordingly, the present invention was devised to solve the aforementioned problems and focuses on providing an improved towing bar structure that allows a shading screen curtain installed inside an agricultural vinyl greenhouse to be arranged in the longitudinal direction with a certain width and easily pulled for replacement even after a certain period of use. By improving the structure of the towing bar, the traction force of the screen curtain is maintained uniformly, stability is enhanced by preventing unilateral sagging that occurs during the opening and closing process, and replacement work can be performed easily.

[0034] This invention relates to an improved structure for a towing bar of a shading screen curtain for agricultural greenhouses, which can reduce installation costs and maintenance time and improve the long-term usage efficiency of the screen curtain. means of solving the problem

[0035] The present invention, for achieving the above technical objectives, comprises a horizontal curtain device for a vinyl greenhouse, comprising, as illustrated in FIG. 1, a frame installed on both sides in the longitudinal direction inside the vinyl greenhouse; a light-blocking screen curtain installed between the two frames and moving along the curtain sliding direction; a towing bar provided inside the two frames; an installation connecting member provided inside the towing bar to secure and move the light-blocking screen curtain; and a wide rope drum provided outside the installation connecting member to wind and open / close the light-blocking screen curtain.

[0036] As illustrated in FIGS. 2 to 9, a towing bar or a towing bar is optionally configured to stably guide and pull the screen curtain in the longitudinal direction, allow for easy replacement even after a certain period of use, maintain uniform pulling force of the screen curtain, and ensure pulling stability.

[0037] As illustrated in FIGS. 2 to 4, the towing bar comprises a main frame having a longitudinal rib hole with a cross-sectional shape having a curved slope on the inside, and a support member having a side locking groove that is open to one side on the upper side of the main frame, and

[0038] The upper side of the support member is provided with a vertical bracket having a bent and curved shape, wherein the upper side is provided with an upper locking groove that opens vertically in the longitudinal direction, the inner side of the vertical bracket is provided with an alignment groove having a bend, and both sides are provided with a tension member having a locking groove and a fixing jaw.

[0039] The opposite end of the tension member is provided with an inclined support surface, and the lower part is provided with a support catch groove extending downward in the longitudinal direction to prevent sagging, and

[0040] In the inner side between the above-mentioned anti-sagging part and tension part, a hooking space is provided so that a bar-shaped hook, sewn longitudinally to both ends of the screen curtain, can be inserted and slid, and a guide part is configured on both sides having an upper hook and a lower hook.

[0041] As shown in FIGS. 4 and 5, a lifting prevention device for preventing the light-blocking screen curtain from lifting is inserted into the upper catch groove and installed to be movable in the longitudinal direction, and a wire is connected to the upper side thereto to fix it, and

[0042] The above anti-lift device comprises a support body having a connecting hole with an elongated hole formed in the center, and an insertion hole is formed to penetrate the lower side of the support body, and support surfaces having locking surfaces are provided on both sides thereof, and the support body and the connecting hole may have cut surfaces.

[0043] As shown in FIG. 5, a sagging prevention device for preventing sagging of the light-blocking screen curtain is inserted into the support catch groove and installed to be movable in the longitudinal direction, and a sagging prevention wire is connected to the inside thereof to be fixed therein, and

[0044] The above-described sagging prevention device comprises a body having an insertion hole formed in the shape of an elongated hole in the center, and on one side of the body, a cut groove is provided with the upper and side sides open, and a tension fixing piece is provided on the front side thereof, and a detachment prevention projection is symmetrically provided on the inner side of the tension fixing piece, and on the other side opposite the body, a through hole is provided, and a detachment prevention piece is symmetrically provided on the inner side thereof, and a support pin is provided on the upper surface of the body, and a locking support piece may be provided on the upper side thereof.

[0045] As illustrated in FIGS. 7 and 8, a safety pressing piece that presses the upper surface of the light-blocking screen curtain and prevents detachment is detachably fixedly supported on the inner side of the tension member, and the safety pressing piece may optionally be provided with a long axis frame or a short axis frame.

[0046] The above safety pressing piece comprises a tension body that is fixedly supported by being engaged with an inner alignment groove, a locking groove, and a fixing jaw of a vertical bracket, and the inside of the tension body is provided with a through-hole shaped rib hole having a curved bevel surface, and the upper side of the rib hole is provided with a curved piece and an alignment jaw that are engaged with the alignment groove and the locking groove, and the lower side of the rib hole is provided with a fixing piece that is engaged and fixed with the fixing jaw, and the inner side between the upper and lower sides of the rib hole is provided with a fastening adjustable tension pressing plate, and the inner side of the tension pressing plate may be provided with an inclined piece.

[0047] As shown in FIG. 7, the bottom surface of the inclined piece may be provided with an anti-detachment piece to prevent the light-blocking screen curtain from detaching, and

[0048] As illustrated in FIG. 9, the towing bar comprises a main frame having a longitudinal rib hole with a cross-sectional shape having a curved slope on the inside, and a support member having a side locking groove that is open to one side on the upper side of the main frame, and

[0049] The upper support portion of the main frame is provided with an inclined bracket, and the upper portion is provided with an upper locking groove that opens toward the upper side, and

[0050] On the outer side of the main frame opposite the upper locking groove, a support locking groove that opens downward is provided, and

[0051] An inclined bracket is provided on the inner side of the above support member, and a catch space is provided on the outer surface of the inclined bracket so that a bar-shaped catch piece, sewn longitudinally to both ends of the screen curtain, can be inserted and slided therein, and a guide member may be configured having an upper catch piece and a lower catch piece on both sides thereof.

[0052] As shown in FIG. 1, a friction-reducing rail bar made mainly of ultra-high molecular weight polyethylene (UHMW-PE) can be inserted into the inner surface of the locking space to reduce resistance to friction of the locking piece and allow it to slide smoothly and be discharged.

[0053] In the above-mentioned catch space, several condensation drainage lines may be provided at the bottom of the main frame to ensure uniform traction force generated during traction due to condensation or freezing caused by temperature differences in winter.

[0054] As illustrated in FIG. 8, the towing bar may have a tension maintaining means capable of generating surface tension by pressing the catch piece of the screen curtain, and

[0055] The above tension maintaining means is provided with a control hole that penetrates vertically through the upper surface of the inclined piece, and a pressure bar that is inserted into the center of the control hole and operates up and down, and a pressure plate is provided on the upper side of the pressure bar, an elastic spring is provided on the upper surface thereof, and a pressure cover is provided to be fixedly installed on the outer side of the elastic spring. Effects of the invention

[0056] The improved towing bar structure for agricultural vinyl greenhouse shading screen curtains according to the present invention as described above is easy and quick to install, which has the effect of reducing costs and time during the construction process.

[0057] The method of unfolding or taking down the standard tent is improved to allow for easy and convenient replacement by pulling it in one direction, and a tow bar is provided to facilitate easy replacement in the longitudinal direction during replacement, which has the advantage of enabling stable operation.

[0058] Screen curtains installed lengthwise with a certain width inside a vinyl greenhouse can be easily and conveniently pulled and replaced even after a certain period of use, which has the advantage of significantly improving maintenance efficiency.

[0059] In addition, by improving the structure of the towing bar, the traction force of the screen curtain is maintained uniformly, and there is an advantage of enabling stable operation by providing an anti-lifting device and an anti-sagging device that prevent lifting and sagging that may occur during the opening and closing process.

[0060] This structural stability reduces user inconvenience and lowers the failure rate of parts, thereby preventing safety accidents for workers, and

[0061] It has the advantage of enabling stable replacement work while preventing the detachment of the catch by providing a safety presser that can prevent safety accidents that may occur when the catch gets caught or detaches during the replacement of the screen curtain, and

[0062] The lower side of the safety pressing piece is equipped with an anti-detachment piece, which has the advantage of increasing stable work efficiency, and

[0063] It has the advantage of enabling stable operation by being equipped with a condensation drainage line that can prevent condensation or freezing caused by temperature differences in winter, and

[0064] In addition, this invention has the advantage of preventing sagging and lifting by maintaining a constant tension through a tension-maintaining means that presses the upper surface of the screen curtain to maintain a constant tension. Brief explanation of the drawing

[0065] FIG. 1 is an exemplary diagram showing the operational state of a conventional vinyl greenhouse horizontal curtain device. FIG. 2 is a side view illustrating an operational embodiment of the present invention. FIG. 3 or FIG. 9 is an exemplary side cross-sectional view of an example of the present invention. FIG. 4 is an exemplary diagram showing the installation state of the lifting prevention device and the sagging prevention device of the present invention. FIG. 5 is a perspective view and a side view of an embodiment of the anti-lifting device of the present invention. FIG. 6 is a perspective view and a side view of an embodiment of the sagging prevention device of the present invention. FIG. 7 is a perspective view of the safety pressing piece of the present invention and an exemplary diagram showing an application embodiment state. FIG. 8 is an exemplary diagram showing a tension maintaining means applied to the safety pressing piece of the present invention. Specific details for implementing the invention

[0066] The improved structure of the towing bar for the shading screen curtain of an agricultural vinyl greenhouse according to the present invention is illustrated in FIGS. 1 to 9,

[0067] A vinyl greenhouse horizontal curtain device (1) comprising, as illustrated in FIG. 1, frames (2) installed on both sides in the longitudinal direction inside the vinyl greenhouse, a light-blocking screen curtain (10) installed between the two frames (2) and moving along the curtain sliding direction, a towing bar (A) provided inside the two frames (2), an installation connecting member (3a) provided inside the towing bar (A) to secure and move the light-blocking screen curtain (10), and a wide rope drum (3) provided outside the installation connecting member (3a) to wind and open / close the light-blocking screen curtain (10).

[0068] As illustrated in FIGS. 2 to 9, a towing bar (A) or a towing bar (A-1) is optionally configured to stably guide and tow the screen curtain (10) in the longitudinal direction, allow for easy replacement after use for a certain period, maintain uniform towing force of the screen curtain (10), and ensure towing stability.

[0070] As illustrated in FIGS. 2 to 4, the example bar (A) is,

[0071] The interior includes a main frame (311) having a rib hole (312) having a cross-sectional shape with a curved slope in the longitudinal direction, and the upper side of the main frame (311) is provided with a support member (310) having a side catch groove (313) that is open to one side, and

[0073] A vertical bracket (321) formed in a bent and curved shape is provided on the upper side of the support member (310), and an upper locking groove (325) that opens vertically is provided in the longitudinal direction on the upper side thereof.

[0074] The vertical bracket (321) has an alignment groove (323) formed with a bend on its inner side, and tension members (320) having a locking groove (322) and a fixing jaw (326) on both sides thereof, and

[0076] The opposite end of the tension member (320) is provided with an inclined support surface (331), and the lower part is provided with a support catch groove (332) that opens downward in the longitudinal direction, thereby providing a sagging prevention member (330).

[0078] A hook space (341) is provided on the inner side between the above-mentioned sagging prevention part (330) and the tension part (320) so that a bar-shaped hook (10a) sewn longitudinally on both ends of the screen curtain (10) can be inserted and slid, and a guide part (340) is configured on both sides with an upper hook (342) and a lower hook (343).

[0080] As shown in FIGS. 4 and 5, the upper catch groove (325) has,

[0081] A lifting prevention device (50) that prevents lifting of the light-blocking screen curtain (10) is inserted and installed so as to be movable in the longitudinal direction, and a wire (50a) is connected to the upper side thereto to fix it, and

[0083] The above lifting prevention device (50) is,

[0084] A support body (56) having a connecting hole (55) formed with an elongated hole in the center, and

[0085] An insertion hole (51) is formed to pass through the lower side of the support body (56), and support surfaces (58) having locking surfaces (52) are provided on both sides thereof.

[0086] The above support body (56) and the connecting hole (55) may be provided with a cut surface (53), and

[0088] As shown in FIG. 5, the support catch groove (332) contains,

[0089] A sagging prevention member (60) for preventing sagging of a light-blocking screen curtain (10) is inserted and installed so as to be movable in the longitudinal direction, and a sagging prevention wire (60a) is connected to the inside thereof to be fixed thereto, and

[0091] The above sagging prevention device (60) is,

[0092] A body (673) having an insertion hole (674) formed in the shape of an elongated hole in the center, and

[0093] One side of the above body (673) is provided with an opening (676) that is open at the top and side, and a tension fixing piece (679) is provided on the front side thereof.

[0094] The inner side of the tension fixing piece (679) is symmetrically provided with anti-detachment projections (675), and

[0095] On the opposite side of the above body (673), a through hole (677) is provided, and on the inner side thereof, a detachment prevention piece (678) is symmetrically provided.

[0096] The upper surface of the above body (673) may be provided with a support pin (672), and a locking support piece (671) may be provided on the upper side thereof.

[0098] As shown in FIGS. 7 and 8, on the inner side of the tension part (320),

[0099] A safety pressing piece (70) that presses the upper surface of the light-blocking screen curtain (10) and prevents detachment is fixedly supported so as to be detachable, and

[0100] The above safety pressing piece (70) may optionally be provided with a long axis frame or a short axis frame, and

[0102] The above safety press piece (70) is,

[0103] A tension body (701) is provided for fixed support by being engaged with the inner alignment groove (323), the catch groove (322), and the fixing jaw (326) of the vertical bracket (321), and

[0104] The interior of the tension body (701) is provided with a through-hole-shaped rib hole (702) having a curved bevel, and

[0105] On the upper side of the above rib hole (702), a curved piece (703) and an alignment jaw (704) that engage with the alignment groove (323) and the catch groove (322) are provided.

[0106] The lower side of the above rib hole (702) is provided with a fixing piece (705) that is fixed by being caught on the above fixing jaw (326), and

[0107] A tension-adjustable plate (706) is provided on the inner side between the upper and lower sides of the above rib hole (702), and

[0108] An inclined piece (708) may be provided on the inner side of the tension pressing plate (706), and

[0110] As shown in FIG. 7, on the bottom surface of the inclined piece (708),

[0111] A detachment prevention piece (709) that prevents the light-blocking screen curtain (10) from detaching may be provided, and

[0113] As shown in FIG. 9, the example bar (A-1) is,

[0114] The interior includes a main frame (311-1) having a rib hole (312-1) having a cross-sectional shape with a curved slope in the longitudinal direction, and the upper side of the main frame (311-1) is provided with a support member (310-1) having a side catch groove (313-1) that is open to one side, and

[0116] The upper support portion (310-1) of the main frame (311-1) is provided with an inclined bracket (321-1), and the upper portion is provided with an upper catch groove (325-1) that opens toward the upper side.

[0118] On the outer side of the main frame (311-1) opposite the upper catch groove (325-1), a support catch groove (332-1) that opens downward is provided, and

[0120] An inclined bracket (331-1) is provided on the inner side of the support member (310-1), and a catch space (341-1) is provided on the outer surface of the inclined bracket (331-1) so that a bar-shaped catch piece (10a), which is sewn in the longitudinal direction to both ends of the screen curtain (10), can be inserted and slided therein, and a guide member (340-1) can be configured having an upper catch piece (342-1) and a lower catch piece (343-1) on both sides thereof.

[0122] As shown in FIG. 1, on the inner surface of the catch space (341),

[0123] A friction-reducing rail bar (900) made of ultra-high molecular weight polyethylene (UHMW-PE) as the main component can be inserted to reduce the resistance to friction of the catch piece (10a) and allow it to slide smoothly and be discharged.

[0125] In the above-mentioned catch space (341),

[0126] In order to secure a uniform traction force when traction is caused by condensation or freezing due to the temperature difference in winter, several condensation drainage lines (910) may be provided at the bottom of the main frame (311).

[0128] As shown in FIG. 8, the example bar (A) above includes,

[0129] A tension maintaining means (800) capable of generating surface tension by pressing the catch piece (10a) of the screen curtain (10) can be maintained, and

[0131] The above tension maintaining means (800) is,

[0132] The upper surface of the inclined piece (708) is provided with an adjustment hole (750) that penetrates vertically, and

[0133] A pressure bar (801) is provided that is inserted into the center of the above adjustment hole (750) and operates up and down.

[0134] A pressure plate (802) is provided on the upper side of the pressure bar (801), and an elastic spring (810) is provided on the upper surface thereof.

[0135] A pressure cover (820) is provided to be fixedly installed on the outer side of the elastic spring (810).

[0137] Hereinafter, each component of the improved structure of the shading screen curtain towing bar for agricultural vinyl greenhouses according to the present invention will be described in more detail as follows.

[0139] Frames (2) are installed according to the internal size of the greenhouse at intervals of up to 8m on both sides in the longitudinal direction, as shown in FIG. 1, inside the greenhouse installed for crop cultivation.

[0140] In the meantime, various cultivation facilities such as open fields and elevated structures necessary for crop growth are installed, and a shading screen curtain (10) that moves along the curtain sliding direction from one side to the other between the two frames (2) is used to maintain uniform irradiation levels and internal and external temperatures during crop cultivation.

[0141] A horizontal curtain device (1) for a vinyl greenhouse is provided, which operates by traction force, by connecting an installation connecting member (3a) installed on the other side to a wide rope drum (3) and connecting the two ends of the shading screen curtain (10) to be uniformly pulled through a towing bar (A) on the upper side of the above-mentioned two-sided frame (2).

[0143] As shown in FIGS. 2 to 9, the screen curtain (10) can be stably guided and pulled in the longitudinal direction, easily replaced after a certain period of use, and the pulling bar (A) or pulling bar (A-1) can be provided to ensure pulling stability while maintaining a uniform pulling force of the screen curtain (10), thereby increasing work efficiency and durability and extending the usage time.

[0145] As illustrated in FIGS. 2 to 4, the example bar (A) is,

[0146] The interior includes a main frame (311) having a rib hole (312) with a cross-sectional shape having a curved slope in the longitudinal direction, so as to maintain a solid binding support force when fixedly installed on the two side frames (2), and so as to allow the hook piece (10) sewn to both ends of the longitudinal screen curtain (10) to be easily guided while maintaining durability, and the upper side of the main frame (311) is provided with a side hook groove (313) that opens to one side, so as to selectively insert a rubber barrier (not shown) or the like to block external air and prevent moisture from penetrating inside, thereby providing stable performance.

[0147] As shown in FIG. 3, the upper side of the support member (310) is provided with a vertical bracket (321) that can achieve a constant variable tension in a bent and curved shape, and operates to have an elastic force that facilitates the attachment and detachment of the safety pressing piece (70) from the inside.

[0148] On the upper side of the above vertical bracket (321), an upper locking groove (325) that opens vertically is provided in the longitudinal direction, and an anti-lifting device (50) that can be selectively fastened from the outside is easily detachably installed and used, thereby ensuring durability and support so as to increase the fastening support of the wire (50a) through a sturdy rib structure.

[0149] The inner side of the vertical bracket (321) is provided with an alignment groove (323) that has a bend formed therein, and on both sides thereis a locking groove (322) and a fixing jaw (326) are provided to provide a tension part (320) that can increase the fastening support force of the safety pressing piece (70), thereby operating to increase stable fastening support efficiency.

[0150] At the opposite end of the tension member (320), an inclined support surface (331) is provided to provide a stable contact guide surface of the screen curtain (10) to increase durability, and at the lower side, a support catch groove (332) that opens downward is provided in the longitudinal direction to allow the sagging prevention device (60) to be fixedly installed, thereby enabling simultaneous correction of lifting and sagging.

[0151] A guide part (340) is provided with an upper hook (342) and a lower hook (343) so that a bar-shaped hook (10a), sewn longitudinally on both ends of the screen curtain (10), is inserted into the inner side between the above-mentioned anti-sagging part (330) and the tension part (320) to allow sliding, thereby securing a space for smooth movement inside, so that stable operation of the screen curtain (10) is achieved.

[0153] As shown in FIGS. 4 and 5, as shown in FIG. 2, a plurality of anti-lifting members (50) are inserted into the upper locking groove (325) to prevent lifting of the light-blocking screen curtain (10) and are installed so as to be movable in the longitudinal direction. Two wires (50a) are connected to the anti-lifting members (50) to maintain constant tension and support them, thereby preventing the screen curtain (10) from lifting due to wind or internal / external pressure differences.

[0155] The above anti-lift device (50) is provided with a support body (56) having a connecting hole (55) with an elongated hole formed in the center, so that a wire (50a) can be inserted along the cut surface (53) to be easily fixed.

[0156] An insertion hole (51) is formed to penetrate the lower side of the support body (56), and support surfaces (58) having locking surfaces (52) are provided on both sides thereof so that they can be easily fastened and fixed to the upper locking groove (325) and move smoothly in the longitudinal direction.

[0158] As shown in FIGS. 3 to 6, several anti-sagging members (60) that prevent sagging of the light-blocking screen curtain (10) are inserted into the support catch groove (332) so that the user can selectively adjust the position and spacing in the longitudinal direction for installation, and an anti-sagging wire (60a) is connected to and fixed to the anti-sagging members (60) inside the support catch groove (332).

[0160] The above sagging prevention device (60) can be inserted and fixed by a body (673) having a wire (60a) that is inserted into and fixedly installed in an insertion hole (674) that is formed in the shape of an elongated hole in the center, and

[0161] On one side of the body (673), an opening (676) is formed with an open top and side, and a tension fixing piece (679) is provided on the front thereof so as to fix and support the wire (60a) by a constant tension force.

[0162] Inside the above-mentioned fixing piece (679), anti-detachment protrusions (675) are arranged symmetrically in the upper and lower directions to prevent the inserted wire (60a) from easily coming out.

[0163] On the opposite side of the above body (673), a through hole (677) is provided, and on the inner side thereis, a detachment prevention piece (678) is provided symmetrically in the upper and lower directions to increase the efficiency of the wire (60a) being caught.

[0164] The upper surface of the body (673) is provided with a support pin (672), and a catch support piece (671) is formed on the upper side thereof so that it operates to be easily fastened and fixed to the support catch groove (332).

[0166] As shown in FIGS. 7 and 8, a safety pressing piece (70) that presses the upper surface of the light-blocking screen curtain (10) and prevents detachment is fixedly supported by a worker pressing it on the inner side of the tension part (320) in a detachable manner, and the safety pressing piece (70) can be optionally equipped with a long axis frame or a short axis frame as needed so that it can be customized for use according to the usage environment.

[0168] As illustrated in FIGS. 7 and 8, the safety pressing piece (70) is equipped with a tension body (701) that is fixedly supported by being caught in the inner alignment groove (323), the catch groove (322), and the fixing jaw (326) of the vertical bracket (321), thereby ensuring solid support by being caught at three points simultaneously.

[0169] The interior of the tension body (701) is provided with a through-hole-shaped rib hole (702) having a curved bevel surface to increase durability and support.

[0170] On the upper side of the above rib hole (702), a curved piece (703) of the same shape and an alignment jaw (704) that engage with the alignment groove (323) and the catch groove (322) are provided so as to be secured by catch when fastened.

[0171] A fixing piece (705) that is fixed to the fixing jaw (326) is provided on the lower side of the above rib hole (702) to obtain a stable locking force, and

[0172] A tension pressing plate (706) is provided on the inner side between the upper and lower sides of the above rib hole (702) so that the operator can adjust the gap by pressing to ensure quick and easy engagement with the inner side of the tension part (320) of the towing bar (A).

[0173] The inner side of the tension pressing plate (706) is provided with an inclined piece (708) to press the upper surface of the screen curtain (10), thereby operating to increase stability against lifting.

[0175] As shown in FIGS. 7 and 8, the bottom surface of the inclined piece (708) is provided with a pin-shaped anti-detachment piece (709) to prevent the light-blocking screen curtain (10) from detaching, thereby maintaining stable traction so that it does not detach during operation.

[0177] As shown in FIG. 3, a friction-reducing rail bar (900) made of ultra-high molecular weight polyethylene (UHMW-PE) is inserted into the inner surface of the catch space (341) to reduce resistance to friction of the catch piece (10a) and allow it to slide smoothly and be discharged, thereby minimizing friction with the catch piece (10a) and minimizing frictional resistance.

[0179] As shown in FIG. 7, the hanging space (341) is provided with several condensation drainage lines (910) at the bottom of the main frame (311) to ensure uniform traction force caused by condensation or freezing due to the temperature difference in winter, thereby preventing the accumulation of moisture caused by condensation on the screen curtain (10) and the hanging piece (10a), and thus preventing damage or friction caused by freezing in winter.

[0181] As illustrated in FIG. 8, the tension maintaining means (800) is provided with a control hole (750) that penetrates vertically through the upper surface of the inclined piece (708), and operates to ensure stable pushing operation through a pressure bar (801) that is inserted into the center and operates up and down.

[0182] A pressure plate (802) is provided on the upper side of the pressure bar (801), and the upper surface is operated to generate a constant pressing force by means of an elastic spring (810).

[0183] A pressure cover (820) is fixedly installed on the outer side of the elastic spring (810) to maintain a constant elastic force uniformly, thereby pressurizing the stable screen curtain (10) and maintaining a constant tension.

[0185] As illustrated in FIG. 9, the towing bar (A-1) is provided with a main frame (311-1) having a rib hole (312-1) having a cross-sectional shape with a curved slope on the inside in the longitudinal direction to ensure robust durability, and

[0186] The upper support portion (310-1) of the main frame (311-1) is provided with an inclined bracket (321-1), and on the upper side thereis, a side catch groove (313-1) and a support catch groove (332-1) that are vertically open at the outer end are symmetrically provided so that the sagging prevention portion (60) can be fastened vertically to prevent lifting and sagging.

[0187] An inclined bracket (331-1) is provided on the inner side of the support member (310-1), and a guide member (340-1) is provided on both sides with an upper hook (342-1) and a lower hook (343-1) so that a bar-shaped hook (10a), sewn longitudinally to both ends of the screen curtain (10), is inserted into the outer surface of the inclined bracket (331-1) and slides therein to increase the hooking force, thereby operating to increase stable traction force. Explanation of the symbols

[0188] A,A-1: Towing bar 1: Horizontal curtain device 2: Frame 3: Wide Rope Drum 3a: Installation connecting member 10: Shading screen curtain 50a: Wire 51: Insertion hole 52: Obstruction surface 53: Cut surface 55: Connection hole 56: Support body 58: Support surface 60: Deflection prevention device 60a: Wire 70: Safety press piece 310,310-1: Support section 311,311-1: Mainframe 312, 312-1: Rib hole 313, 313-1: Side catch groove 320: Tension part 321, 321-1: Vertical bracket 322: Locking groove 323: Alignment groove 325, 325-1: Upper catch groove 326: Fixing jaw 330: Anti-sagging part 331, 331-1: Inclined support surface 332, 332-1: Support catch groove 340, 340-1: Guide part 341,341-1: Catching space 342,342-1: Upper catching piece 343,343-1: Lower catch piece 50: Lift-prevention device 671: Locking support piece 672: Support pin 673: Body 674: Insertion hole 675: Anti-slip protrusion 676: Incision groove 677: Through hole 678: Anti-detachment piece 679: Tension fixing part 701: Tension body 702: Rib hole 703: Curved section 704: Alignment jaw 705: Fixing piece 706: Tension pressing plate 708: Inclined piece 709: Anti-detachment piece 750: Adjustment hole 800: Tension maintaining means 801: Pressure bar 802: Pressure plate 810: Elastic spring 820: Pressure cover 910: Condensation drainage line

Claims

Claim 1 A vinyl greenhouse horizontal curtain device (1) comprising: frames (2) installed on both sides in the longitudinal direction inside the vinyl greenhouse; a light-blocking screen curtain (10) installed between the two frames (2) and moving along the curtain sliding direction; a towing bar (A) provided inside the two frames (2); an installation connecting member (3a) provided inside the towing bar (A) to secure and move the light-blocking screen curtain (10); and a wide rope drum (3) provided outside the installation connecting member (3a) to wind and open / close the light-blocking screen curtain (10). The device further comprises a towing bar (A) or a towing bar (A-1) that is selectively configured to stably guide and tow the screen curtain (10) in the longitudinal direction, to be easily replaced after use for a certain period, and to maintain uniform towing force of the screen curtain (10) while ensuring towing stability. The towing bar (A) has rib holes (312) having a cross-sectional shape with a curved slope on the inside, arranged in the longitudinal direction. The invention comprises a main frame (311) and a support member (310) having a side locking groove (313) that is open to one side on the upper side of the main frame (311); a vertical bracket (321) formed in a bent and curved shape is provided on the upper side of the support member (310), with an upper locking groove (325) that is open vertically on the upper side and provided in the longitudinal direction thereon, and an alignment groove (323) that is bent is provided on the inner side of the vertical bracket (321), and a tension member (320) having a locking groove (322) and a fixing jaw (326) on both sides thereof; and an inclined support surface (331) is provided on the opposite end of the tension member (320), and a sagging prevention member (330) having a support locking groove (332) that is open to the lower side and provided in the longitudinal direction on the lower side thereon, and the A hooking space (341) is provided on the inner side between the sagging prevention part (330) and the tension part (320) so that a bar-shaped hook (10a), sewn longitudinally to both ends of the screen curtain (10), can be inserted and slid.An improved structure for a towing bar for an agricultural vinyl greenhouse shading screen curtain, characterized by having a guide section (340) formed on both sides, the guide section (340) having an upper hook (342) and a lower hook (343). Claim 2 An improved structure for a shading screen curtain towing bar for an agricultural vinyl greenhouse, characterized in that, in the first paragraph, a lifting prevention member (50) that prevents lifting of the shading screen curtain (10) is inserted into the upper locking groove (325) and installed so as to be movable in the longitudinal direction, and a wire (50a) is connected to the upper side to fix it, and the lifting prevention member (50) is provided with a support body (56) having a connecting hole (55) with an elongated hole formed in the center, and an insertion hole (51) is formed to penetrate the lower side of the support body (56), and a support surface (58) having a locking surface (52) is provided on both sides, and a cut surface (53) is formed in the support body (56) and the connecting hole (55). Claim 3 In claim 1, a sagging prevention member (60) for preventing sagging of the light-blocking screen curtain (10) is inserted into the support catch groove (332) and installed so as to be movable in the longitudinal direction, and a sagging prevention wire (60a) is connected and fixed to the inside thereof, and the sagging prevention member (60) is provided with a body (673) having an insertion hole (674) formed in the shape of an elongated hole in the center, and on one side of the body (673), a cut groove (676) is provided with the upper and side sides open, and a tension fixing piece (679) is provided on the front side thereof, and a detachment prevention projection (675) is symmetrically provided on the inside of the tension fixing piece (679), and on the other side of the body (673), a through hole (677) is provided, and a detachment prevention piece (678) is symmetrically provided on the inside thereof, and the body (673) An improved structure for a towing bar for an agricultural vinyl greenhouse shading screen curtain, characterized by having a support pin (672) on the upper surface and a hooking support piece (671) formed on the upper side. Claim 4 An improved structure for a towing bar for an agricultural vinyl greenhouse shading screen curtain, characterized in that, in the first aspect, a safety pressing piece (70) that presses the upper surface of the shading screen curtain (10) and prevents detachment is detachably fixedly supported on the inner side of the tension part (320), and the safety pressing piece (70) is optionally provided with a long axis frame or a short axis frame. Claim 5 In claim 4, the safety pressing piece (70) comprises a tension body (701) that is fixedly supported by being caught in the inner alignment groove (323), the catch groove (322), and the fixing jaw (326) of the vertical bracket (321); the inside of the tension body (701) is provided with a through-hole-shaped rib hole (702) having a curved bevel surface; the upper side of the rib hole (702) is provided with a curved piece (703) and an alignment jaw (704) that are caught in the alignment groove (323) and the catch groove (322); the lower side of the rib hole (702) is provided with a fixing piece (705) that is fixedly caught in the fixing jaw (326); the inner side between the upper and lower sides of the rib hole (702) is provided with a fastening adjustable tension pressing plate (706); and the tension pressing plate (706) An improved structure for an agricultural vinyl greenhouse shading screen curtain towing bar, characterized by having an inclined piece (708) on the inner side. Claim 6 An improved structure for a shading screen curtain towing bar for an agricultural greenhouse, characterized in that, in claim 5, the bottom surface of the inclined piece (708) is provided with a detachment prevention piece (709) to prevent the shading screen curtain (10) from detaching. Claim 7 In claim 1, the towing bar (A-1) comprises a main frame (311-1) having a rib hole (312-1) in the longitudinal direction having a cross-sectional shape with a curved slope on the inside, and a support member (310-1) having a side locking groove (313-1) that is open to one side on the upper side of the main frame (311-1), and an inclined bracket (321-1) is provided on the upper support member (310-1) of the main frame (311-1), and an upper locking groove (325-1) that is open to the upper side is provided on the upper side, and a support locking groove (332-1) that is open to the lower side is provided on the outer side of the main frame (311-1) opposite the upper locking groove (325-1), and an inclined bracket (331-1) is provided on the inner side of the support member (310-1). An improved structure for a towing bar of a shading screen curtain for an agricultural vinyl greenhouse, characterized by having a guide section (340-1) formed on both sides of the inclined bracket (331-1) such that a bar-shaped hook (10a), sewn longitudinally at both ends of the screen curtain (10), is inserted and slides therein. Claim 8 An improved structure for a towing bar for an agricultural vinyl greenhouse shading screen curtain, characterized in that, in the first paragraph, a friction-reducing rail bar (900) made of ultra-high molecular weight polyethylene (UHMW-PE) is inserted into the inner surface of the locking space (341) to reduce resistance to friction of the locking piece (10a) and allow it to slide smoothly and be discharged. Claim 9 An improved structure for a towing bar for an agricultural vinyl greenhouse shading screen curtain, characterized in that, in the first paragraph, the above-mentioned hanging space (341) has several condensation drainage lines (910) configured at the bottom of the main frame (311) to ensure uniform traction force generated when towing due to condensation or freezing caused by a temperature difference in winter. Claim 10 An improved structure for an agricultural vinyl greenhouse shading screen curtain towing bar according to claim 1, characterized in that the towing bar (A) comprises a tension maintaining means (800) capable of generating surface tension by pressing a catch piece (10a) of the screen curtain (10). Claim 11 An improved structure for a towing bar for an agricultural vinyl greenhouse shading screen curtain, characterized in that, in claim 10, the tension maintaining means (800) is configured to have a control hole (750) that penetrates vertically through the upper surface of an inclined piece (708), a pressure bar (801) that is inserted into the center of the control hole (750) and operates up and down, a pressure plate (802) is provided on the upper side of the pressure bar (801), an elastic spring (810) is provided on the upper surface thereof, and a pressure cover (820) is fixedly installed on the outer side of the elastic spring (810). Claim 12 delete

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