Directly affects production and installation, the door cover structure of hardcover doors can be designed like this

Finely decorated residential wooden parts mainly include wooden doors, cabinets, wood veneers, lines, etc. With the improvement of the automation and intelligence level of wooden doors in our country, the production efficiency of wooden doors has been greatly improved, and the product quality has become more stable. At the same time, the wooden door structure is also required to adapt to the needs of this high-efficiency and large-scale production. However, there are still some problems in my country\’s wooden door standard system, such as large door opening size deviations, messy standards, incomplete standards related to wooden doors, and incomplete standards for wooden door-related accessories.

01 The composition and classification of door covers

Wooden door covers are originally simple frame structures. Then connect the door frame to the pre-embedded wooden bricks in the wall. In the past, in the construction and decoration industry, the decorative panels of door frames were often called package panels. With the technological development of the wooden door industry and the decoration industry, the traditional installation and construction of vertical openings has evolved into the factory-processed partsRear plug installationModel, the traditional door frame is gradually replaced by the door frame of the set door.

Door covers are generally made ofDoor cover panels, door cover lines and door blocking stripsComposed of three parts, a shock-absorbing sealing strip is installed on one side of the door blocking strip to buffer the impact of the door leaf on the door cover and ensure the sealing of the door leaf. In the construction of finely decorated residential buildings, generally the door panels are pushed into the door opening after assembly, and are connected to the base of the wall through foam glue. Finally, the glue joint between the door panels and the wall is covered with the door panel line, and the installation is closed. (As shown below).

Common door frame structures

According to the opening method of wooden doors, door covers can be divided into swing door door covers , sliding door door covers, folding door door covers, pass door covers, hidden door door covers, etc. This article mainly focuses on the most common door covers in finely decorated residencesHinged door door cover、Secret door door coverCarry out structural optimization design.

02 What requirements should door frames meet

Wooden doors are made of door leaves fixed on the door cover through hinges or other hardware. Compared with the door leaf, the door cover does not have high decorative requirements. In terms of function, it must meet the following points:

(1) Good load-bearing and bending resistance

The dead weight of the wooden door is transferred to the door cover through the hinges, supporting and ensuring the normal opening and closing of the wooden door. Special hardware for wooden doors such as hidden door closers, access control, smart locks, hydraulic self-closing leaves, floor springs, etc. must also be installed On wooden doors, holes and grooves need to be made in the door pocket, so the material for making the door pocket needsResistance to deformation and good nail holding power\’s solid wood, plywood, blockboard, wood-plastic composite materials, etc. In general factory processing, in order to improve production efficiency, prevent wood deformation, and enhance nail-holding strength, it is often usedPlywood serves as the base material for door casings.

(2) Good moisture resistance

The door cover has been placed directly on the ground for a long time. If the moisture resistance is poor, quality problems such as mold and glue opening will occur. oftenThe standard method is to carry out moisture-proof treatment on the contact surface between the back and the wall and the contact surface between both ends and the ground. Common methods include paint sealing, asphalt paint sealing, covering with moisture-proof boards, etc. Medium-density fiberboard is not suitable to be directly used as the base material for door panels because it is prone to swelling and mold when exposed to moisture. Some factories set up plastic mats</strong at the contact areas between the door pockets and the ground >, after the door cover is installed, there will be a gap of 3-5mm from the ground, and it should be closed with moisture-proof sealant. This practice is worth promoting.

(3) Size requirements

Because the door panel has to bear the weight of the door leaf, it is generally required that the thickness of the hinge part is D1 ≥ 25mm. If the door leaf is overweight, the size of the door pocket should be increased accordingly. If a hidden door closer is installed, the door blocking strip thickness D2 ≥ 15mm.

03 Connection structure of door panels

Door cover panels are generally composed of three boards. Before installing the door cover, you need to assemble and connect the top cover panel and the two vertical cover panels on both sides to form a \”door\”-shaped door. The cover plate assembly is then pushed into the door opening. There are two types of connection between the top cover plate and the side cover plate: 45° angle connection and shoulder-cut right angle connection (see table below). p>

Among them, the right-angle connection method of shoulder-cut and tenon is more convenient. At present, domestic 45° angle door panels are usually connected by tenon pieces and steel clips, which require special tools, so the right-angle connection of shoulder-cut and tenon is more popular.

Connection method	Structural features
	45° angles have beautiful appearance and wide applicability; Suitable for industrial mass production; High requirements for processing accuracy; The corners are prone to misalignment during connection, so you need Specialized grooving equipment and tools.
	Use wood screws to connect from the back of the door panel, easy to assemble; The connection is firm and will not cause misalignment; No special equipment and tools required.

Door panel connection structure

04 Structure design of door cover line

Door cover line is also called face panel or mouth line. It covers the foam rubber gaps, corners and the side of the door cover panel against the wall. The external curve shape plays a decorative role. With the continuous changes in modern decoration styles, people are increasingly advocating simple design styles,doors The set of threads also tends to be simple in shape. Withone-line door cover lineFor example, design the door cover line structure.

A-type door cover line structure is assembled first and then skinned, and B-type door cover line structure is skinned first and then assembled. When the surface is mixed with paint, If the A-type door frame structure is not covered with wood veneer, the side joints will easily crack;

Before assembly	After assembly

The structure of the door frame line

B-type structure door cover lines and inserts are combined at a 45° angle. There are no seams on the sides and there will be no side cracks. It is suitable for small batch processing. Therefore, large enterprises in order to achieve Mass production, usually A-type structure is usedProfessional equipment covers the door casings with veneer and then mixes paint. When the shape of the door frame is more complex and needs to be covered with wood veneer, varnish is commonly used to reflect the texture of the wood grain. Type A and Type B can also be selected according to the actual situation.

When the production enterprise does not have special coating equipment and professional and technical workers, the B-type structure can be used for small batch production. On the contrary, for Fine decoration batch orderCan be used for productionA-type structure, to achieve batch production and automation.

05 Structural design of door frames

(1) Structural design of swing door door pockets

Gate Commonly used structures include stepped structure, German T-shaped door cover structure and door bar structure. Step structureGood aesthetics, reasonable stress, and stable structure. Commonly found in mid- to high-end products such as paint and solid wood. However, the process is complex and there are few specialized processing equipment. Factories generally use manual nailing because there are steps. , it is also not conducive to UV coating.

Model	Door cover structure diagram
Type A (door bar type)
Type B (combined)
Type C (combination Formula)

Hinged door door cover structure

German T-shaped doorThe door cover\’s door cover plate and door blocking strip are integrated into one, which has the advantage of good sealing performance. The disadvantages are the inconvenience of installation, adjustment and later maintenance, and the lack of changes in the shape of the door cover line. The processing of T-shaped door pockets requires some special equipment and hardware, and uses special three-hinge hinges and eccentric locks.

Door-bar type structureThe characteristic is that the door-bar is processed separately and then combined with the door Kit assembly. It has a simple structure, easy processing, and low production cost, and can realize industrial production. However, the adjustable width is limited, making it inconvenient for batch installation.

In order to adapt to the mass production and installation of finely decorated residences, many companies are currently exploring research and development Combined door frames, Combined door panels generally split the original overall door panel into two parts: the main door panel and the auxiliary door panel, or they are composed of the main door panel, the auxiliary door panel and the door blocking strip. The main door cover refers to the door cover where door locks and hinges are installed. The size is relatively fixed. After the optimized design of the combined door cover, the auxiliary door cover can be expanded and contracted according to the thickness of the wall.

Model	Door cover structure diagram
D type (optimized combination)
E type (optimized combination)
F type (optimized combined type)
G type (optimized combined type)

Hinged door door cover structure

The three types of door covers A, B, and C have a small telescopic range. When installing a single set of residential wooden doors or a small number of residential wooden doors, you can choose one of them. There are four optimized combination door covers of D, E, F, and G. The scalable range is large and can meet the requirements for mass production and installation of finely decorated residential wooden doors.F and G combined door cover main and auxiliary door cover panels are relatively simple in shape and easy to process, which can greatly improve production efficiency.

(2) Structural design of secret door door cover

Secret door is also called \”invisible door\”, that is, the door and the wall are visually integrated without destroying the overall shape of the wall. The appearance makes the wall beautiful and unified, and improves the sense of space. Secret doors are mainly used in spaces with high privacy requirements or in places where Feng Shui taboos need to be avoided. The outer surface material and craftsmanship of the secret door leaf must be consistent with the wall surface. Sometimes it is equipped with a single-sided invisible handle lock so that the handle cannot be seen from the outside to achieve the best invisible effect.

Secret doors are divided into outward-opening secret doors and in-open secret doors. For outward-opening secret doors, the wall panel is usually made flat with the door. A handle groove can be milled on one side of the door, or a door handle can be installed. As shown in the figure below, the A and B sets of panels are processed separately in the factory. The A and B sets of panels are connected through tenons at the installation site and are glued to increase their strength.

Outward-opening secret door door cover structure 1

Because hinges need to be installed on the A set, a thickened strip is added to the back to increase its strength. If there is a door cover wire on the inside of the door cover board, the B cover panel can be slotted and connected through the door cover wire insert. The insertion depth of the door cover wire insert can adapt to the width of different walls (picture below).

Outward-opening secret door door cover structure 2

Inside-opening secret doors are commonly used in finely decorated residences. Compared with outward-opening secret doors, they are more convenient to use. The handle is usually installed on the inside, which will not affect the overall effect. As shown in the figure below (Inward-opening secret door door cover structure 1), the inner-opening secret door door cover structure 1. The wall panel is connected to the door cover plate through the tenon piece, and the door cover line is connected to the door cover plate through the insert piece. It can be adjusted according to the wall Width variation adjusts the depth of the insert.

Inward-opening secret door door cover structure 1

Inward-opening secret door door cover structure 2

Deepen the structure one, the wall panels can also be replaced with door cover lines, and the door cover panels are divided into two parts (the door cover structure two of the inner-opening secret door in the picture above).

The structure of the wooden door cover directly affects the production and installation of the wooden door. The production company can choose the appropriate door cover structure according to the scale of the enterprise and the actual situation of the project. On the basis of considering the cost, the door cover structure can be adjusted in a wide range , can adapt to walls with large size deviations, and can be used as a product standard for enterprise door cover design. At the same time, appropriate hardware must be selected for different door cover structures to ensure the normal use of the product.