JPH089162B2 - Method and device for injecting liquid into wood - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method and an apparatus for injecting a treatment liquid such as a resin into wood.

[Conventional technology]

Conventionally, various injection methods and devices of this type are known, and various treatment liquids are injected into wood to make wood flame-retardant,
Stabilize the dimensions, improve the strength, enhance the anticorrosion and insect repellency, and further expand the application by dyeing,
The product value is increasing.

In these conventional methods and apparatuses, the wood to be treated is stored in an empty tank in advance, and the air in the tank is first vacuumed to reduce the pressure in the tank. After the pressure reduction process in the tank is completed, a treatment liquid such as a resin liquid is put in the tank while maintaining the reduced pressure state. Finally, the inside of the tank is pressurized so that the treatment liquid is injected into the wood to be treated.

[Problems to be Solved by the Invention]

By the way, in the conventional method, the reason why the treatment liquid is put into the tank after depressurizing the treated wood is that if the treatment liquid is put into the tank from the beginning, the air in the timber will escape. Depending on the treatment liquid, it may adhere to the wood surface such as the ostium of the wood to be treated during decompression depending on the treatment liquid and block some of the holes necessary for the liquid to enter, resulting in a uniform treatment liquid injection state. This is because there is a case where you cannot get the information.

However, according to such a method, it is possible to increase the number of working steps as compared with the case where the wood and the treatment liquid are put in the tank from the beginning in order to put the treatment liquid while keeping the depressurized state in the tank. Of course, an extra control device, valves, etc. are required, and improvement has been desired.

[Means for solving the problem]

The method for injecting a liquid into wood according to the present invention is to depressurize the inside,
A method for injecting a liquid such as a resin liquid into wood in a pressurizable tank, which comprises the following steps.

In the first step, the treated wood to be injected is mounted on a truck, the truck is stored in the tank, and then the tank is filled with the liquid.

In the second step, the air in the tank is vacuum-sucked to reduce the pressure in the tank, and the air existing in the treated wood together with the air in the tank is discharged to the outside of the wood.

And in the final third step, after the above decompression is completed,
While the liquid inside the tank is pressurized by the pressure pump to pressurize the inside of the tank, the liquid inside the tank is opened to the atmospheric pressure by the valve opening so that the pressure inside the tank does not drop sharply by the valve operation, The liquid is injected into the treated wood while discharging residual air existing in the liquid in the tank or on the surface of the treated wood to the outside of the tank.

Further, instead of the step of opening the liquid in the tank to the atmospheric pressure via a valve, a vacuum suction line from the inside of the tank is provided separately from the vacuum suction line, and the same or similar to the treated wood is provided in the middle thereof. A step of discharging air existing in the liquid or on the surface of the wood to be treated to the outside of the tank by interposing a monitor wood having a property, by vacuum suction in the tank, and providing the monitor device It is also possible to have a step of confirming completion of the injection process by visually observing the dropping of the liquid from the monitor wood through the monitoring window.

The liquid injection device for wood according to the present invention is mainly a tank whose inside is depressurized and pressurizable, a trolley for mounting the processed wood to be injected with the liquid and storing it in the tank,
Vacuum the air in the tank to reduce the pressure in the tank,
Vacuum suction means for discharging the air in the tank to the outside of the tank and discharging the air existing in the wood to be processed to the outside of the wood, the pressure in the tank for the liquid in the tank sharply decreases A valve is provided which is opened to atmospheric pressure with an opening not to discharge air bubbles existing in the liquid or adhering to the surface of the treated wood to the outside of the tank.

Further, instead of the valve, a monitor device is provided in the middle of a vacuum suction line for sucking the inside of the tank,
The monitor device includes a filter unit connected to the decompression line and a monitor unit integrally provided below the filter unit, and the filter unit has a property similar to or similar to that of the wood in the decompression line. The monitor may be provided with timber connected thereto, and the monitor unit may be provided with a monitoring window for visually observing whether or not the liquid has passed through the monitor member at a position where the liquid that has passed through the monitor member is dropped.

The wood to which the present invention can be applied is not particularly limited, but for example, cedar, Akamatsu, Kuromatsu, Karamatsu, Ezomatsu, Todomatsu, Toga,
Conifers such as fir tree, cypress, straw, spruce, ichii, and asunaro , Rawan, mahogany, apiton, agathis, teak, oak, rosewood, ebony and the like.

Further, the shape of the material to be processed may be any shape that can be mounted in a container, and may be any shape of log, veneer, square and plate. The material to be treated is, of course, lumber as described above, plywood, processed wood such as laminated wood, particle board,
Fiberboard is also acceptable.

Examples of the flame retardant treatment liquid include 2 ammonium hydrogen phosphate, an inorganic water-soluble salt of boric acid, a sulfamate salt, and the like.
A compound containing a flame retardant such as a halogen compound, a compound containing phosphorus and nitrogen, a guanidine compound, a metal oxide such as antimony oxide, etc. can be adopted.

Examples of the treatment liquid for stabilizing the dimension include polyethers such as polyethylene glycol and polypropylene glycol, polyethylene glycol mono (meth) acrylate, saturated polyester resin, poly (meth) acrylic acid esters or copolymers thereof, and urethane. Resin, polyvinyl alcohol, paraffin, vinyl acetate copolymer,
Polyamide resin, polyimino resin, aminoplast resin, fluororesin, silicone resin, vinyl copolymer resin,
Solutions or dispersions of SBR, NBR, etc. can be used.

Examples of the treatment liquid for strengthening include styrene, (meth) acrylate, vinyl acetate, diallyl phthalate,
Monomers represented by divinylbenzene, (meth) acrylic acid, acrylonitrile, vinylidene chloride, unsaturated polyester resin and styrene monomer, reactive polyurethane resin, phenol resin, alkyd resin, urea resin, melamine resin, vinyl ester, epoxy resin, etc. Solutions or dispersions of can be used.

Examples of preservative treatment agents include copper compounds, chromium compounds, arsenic compounds, boron compounds, pentachlorophenol, metal salts of naphthenic acid, organic tin compounds, chloronaphthalene compounds, 8-quinolinol copper compounds, captan compounds,
Treatment solutions containing preservatives such as creosote oil, Wolman salt, and chromized zinc chloride can be mentioned.

Examples of the treatment liquid for insect repellent include Wolman salt,
Polydene salts, organophosphorus compounds, carbamate compounds, organotin compounds, chlordane, heptachlor, dieldrin, aldrin, thiodane, γ-BHC (1,2,3,4,5,6-hexachlorocyclohexane), DDT [1,1.1 -Trichlor-2,2-
Bis (p-chlorophenyl) ethane], methoxychloro [1,1,1-trichloro-2,2-bis (p-methoxyphenyl) ethane], toxaphene, kepon, sulfonamides, thiophene oil, organic thiocyanates, etc. A treatment agent containing an insect repellent may be mentioned.

As a processing solution for dyeing, for example, chrysophenine
Direct dyes such as GX and Direct Brown M, acid dyes such as Suminol First Orange PO and Suminol First Brown R, basic dyes such as safranine and auramine, alcohol-soluble dyes, oil-soluble positive dyes,
If necessary, a solution or dispersion containing a dyeing aid and a surfactant and the like can be mentioned.

As a medium for producing these treatment liquids, for example, water, alcohols, glycols, aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, ketones, esters, halogen compounds, Acids, dioxane, tetrahydrofuran, DMF, DMSO and the like are used.

The viscosity of the treatment liquid used in the present invention is determined by the relationship with the properties of the treated wood, but a viscosity of 1,000 cps or less is generally preferred.

The depressurization treatment in the method of the present invention is preferably performed at an absolute pressure of 160 Torr or less. If the absolute pressure is higher than that, it may be difficult to efficiently remove the gas present in the treated wood.

Pressure treatment in the method of the present invention, a pressure of 1 to 50 kg / cm ^2, is each time, especially at a pressure of 8~50kg / cm ² preferably. The higher the degree of pressurization, the better the injectability of the treatment liquid into the treated wood. However, it should be noted that it may be deformed depending on the applied pressure depending on the properties of the treated wood.

The monitor wood is provided to preferentially discharge the air existing in the treatment liquid or remaining on the surface of the treated wood to the outside of the system and to confirm the permeation of the treatment liquid into the wood. As mentioned above, the mechanism is not clear. It is presumed that the conduit holes in the monitor wood piece may play the role of a filter for separating low molecular weight substances such as air from high molecular weight substances. Of course, the wood piece is preferably a wood piece of the same type of wood as the wood to be treated, but any piece having similarities can be sufficiently adopted.

[Action]

First, the treated wood to be injected is mounted on a trolley, the trolley is stored in the tank, and the tank is filled with a liquid. Incidentally. The air in the tank is sucked by the vacuum suction means to reduce the pressure in the tank. Then, the air existing in the treated wood together with the air in the tank is discharged to the outside of the wood. And finally, when the inside of the tank is pressurized and the inside of the tank is opened to the atmospheric pressure through a valve, the air in the liquid in the tank or on the surface of the treated wood is discharged to the outside of the tank. At the same time, the liquid is injected into the treated wood.

The same applies when a monitor is used instead of the valve. In this case, when the air in the tank is almost exhausted to the outside of the system, the injection liquid subsequently passes through the monitor wood and the monitor device monitors. Start dripping into the department. Since the monitor wood and the wood to be treated have the same or similar properties, it is possible to confirm that the treatment liquid has sufficiently penetrated into the wood to be treated in the tank if this dripping can be visually confirmed through the monitoring window of the monitor section.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

1 to 4 show an embodiment of the present invention.
The liquid injection device for wood of this embodiment mainly includes a pressure vessel 1 whose inside is depressurizable and pressurizable, a trolley 3 for mounting the treated wood 2, and a depressurization inside the pressure vessel 1. Device 4, pressurizing device 6 for supplying compressed air to the depressurizing device 4, pressurizing device for pumping the processing liquid 20 into the pressure vessel 1.
It consists of 18, valve 7.

The pressure vessel 1 is composed of a hollow cylindrical body 8 and a lid 9 which is attached to one end of the body 8 to be openable and closable, and is fixed to the foundation by legs. A depressurizing nozzle 10 and a pressurizing nozzle 11 are provided above the body 8. Decompression nozzle 10 is decompression device 4
The pressurizing nozzle 11 is connected to the pressurizing device 18, respectively. Further, a processing liquid drawing-out pipe 12 is provided below the body 8.

A rail 15 for receiving the carriage 3 is provided in the pressure vessel 1.

A rail 30 is laid on the front side of the lid 9 of the pressure vessel 1. The trolley | bogie 3 can be accommodated in the pressure vessel 1 and taken out from the pressure vessel 1 by the trolley | bogie 31 which runs on this rail 30.

The trolley 3 carries the treated wood 2, and the trolley 3
The treated wood 2 mounted inside the pressure vessel 1 contains the treatment liquid 20.
When it is put in the container, the treated wood 2 can be prevented from rising. When the woods to be treated, particularly the timbers, are closely attached to each other and are mounted on the trolley 3, small pieces of wood, for example, between the woods 2 to be treated are provided so that the air escaped from the wood 2 to be treated can easily escape to above the pressure vessel 1. It is good to sandwich the etc.
However, in the case of logs, such processing is unnecessary. Further, a treatment liquid withdrawing pipe 12 is provided below the pressure vessel 1.

The decompression device 4 vacuum-sucks the air in the pressure vessel 1 to discharge the air in the pressure vessel 1 to the outside, respectively.
It is a vacuum suction means for decompressing the inside and discharging the air present in the treated wood 2 to the outside of the treated wood 2.

The decompression device 4 is for vacuuming the air in the pressure vessel 1 to reduce the pressure inside the pressure vessel 1, and is provided with a plurality of nozzle blocks 25 connected therein.

The nozzle block 25 is a block body as shown in FIG.
The throat 31 is formed within 26, and the front end opening of this throat 31 is formed.
Nozzle 33 is attached to 32. Overall size is about 45m /
m. The front end port 32 of the throat 31 expands in a divergent shape, and the diameter D on the outer end side is set to D = 1,5d with respect to the nozzle hole 33a diameter d of the nozzle 33, and the gap t (0 .
5mm) apart to open. The rear end of the throat 31 is formed in a divergent shape like the front end and is connected to the discharge hole 34.
The base end of the nozzle 33 is screwed into the air 35 provided in the block body 26. Suction port 36 that opens inside this vacant chamber 35
Is connected to the intake hole 37.

In the nozzle 33, the outer shape of the base end part is a cylindrical part 38 from the tip to a slight length (about 0.3 mm), and a conical part that spreads from the base of the cylindrical part 38 (the length is about 2 mm in the axial direction). Has been formed. The nozzle block 25 shown in FIG.
33a is connected to the inflow hole 39 for compressed air. The compressed air inflow hole 39 is connected to the discharge line 61 of the pressurizing device 6 (for example, a compressor), and the intake hole 37 is connected to the depressurizing nozzle 10 via a depressurizing tank in the depressurizing device.

FIG. 3 shows the test results of the depressurizing effect by the depressurizing device constructed by using the nozzle block 25. Decompression target is 90
A vacuum tank having 59 containers, a in the figure is a vacuum degree-time curve when 10 nozzle blocks are connected in parallel, 40 in b, and 68 in c. In addition, the straight lines d to l shown as a comparative example are decompression degree-time straight lines by a vacuum pump manufactured by Sato Vacuum Machinery Co., Ltd. (Address: 1036 Fujikubo, Miyoshi-cho, Iruma-gun, Saitama). The straight lines d to 1 were calculated from the performance chart of FIG. In the figure, the numbers following SW and ST show the pumping speed (l / min), and the numbers following KS show 1/100 of the pumping speed (l / min).

When 68 nozzle blocks 25 are connected (curve c), a considerably stronger vacuum suction force can be exhibited as compared to a vacuum pump of similar price (shown by straight lines h and i in FIG. 3). Recognize. That is, by using this nozzle block 25, a vacuum suction force equivalent to that of an expensive vacuum pump can be obtained at low cost, and the price of the entire system can be reduced. Further, the vacuum pump generally requires regular maintenance in order to maintain its performance, but by using this nozzle block 25, so-called maintenance-free can be achieved. Further, since the number of connections of the nozzle block 25 can be freely adjusted, a desired vacuum class attractive force can be easily obtained, and the system configuration can be easily changed.

The pressurizing device 6 is connected to the depressurizing device 4 and supplies compressed air for vacuum suction to the depressurizing device 4.

The pressure device 18 includes a pressure nozzle 11 on the one hand and a processing liquid 20 on the other hand.
It is connected to the reserve tank 19 of.

The valve 7 is a processing liquid withdrawal pipe provided under the pressure vessel 1.
Connected to 12, the processing liquid 20 in the pressure vessel 1 is opened to atmospheric pressure to the extent that the pressure in the pressure vessel 1 does not drop sharply. Then, by opening the valve 7, bubbles existing in the treatment liquid 20 or adhering to the surface of the treated wood 2 are efficiently discharged to the outside of the pressure vessel 1 simultaneously with the liquid. In this case, the gas has a lower viscosity than the liquid, and when the valve 7 is opened, the gas is better than the liquid in the pressure vessel 1.
Since the tendency to go out is large, it is possible to efficiently discharge the bubbles in the pressure vessel 1 simultaneously with the liquid to the outside of the pressure vessel 1 while minimizing the pressure drop in the pressure vessel 1 due to the discharge of the liquid. it can. The valve 7 is opened a little by a manual operation or is intermittently operated by using a solenoid valve to open. A discharge pipe 71 is connected to the valve 7, and the other end of the discharge pipe 71 faces the discharge tank 72. The discharge tank 27 is connected to the reserve tank 19 so that the processing liquid 20 is returned to the reserve tank 19.

 Next, the operation of this embodiment will be described.

First, mount the appropriate number of woods 2 to be processed on the trolley 3,
The treated wood 2 is fixed. Then, the carriage 3 is housed in the pressure vessel 1 using the carriage 31 and the rail 15, and the lid 9 is closed.
In that state, the processing liquid 20 is injected into the pressure vessel 1. Processing liquid
After pouring 20, the amount of wood 2 to be treated is such that the treated wood 2 does not come out.

Next, the pressurizing device 6 is operated to operate the depressurizing device 4,
The pressure reducing nozzle 10 on the upper side of the pressure vessel 1
Reduce the pressure below 160 Torr. After the inside of the pressure vessel 1 exhibits a desired reduced pressure state, the pressure reduction is continued for 10 to 120 minutes.
Thereby, the air in the treated wood 2 is discharged to the outside.

Next, the decompression nozzle 10 on the upper part of the pressure container 1 is closed, and the compressed processing liquid 20 having a pressure of 8 to 40 kg / cm ² is sent into the pressure container 1 by the pressure nozzle 11 on the upper side of the pressure container 1. Pressurization with the compressed processing liquid 20 is continued for about 10-120 minutes.

In this case, the pressure vessel 1 is pressurized by further injecting the processing liquid 20 which should have already been filled in the pressure vessel 1.
First, it is because the treatment liquid 20 enters the inside of the wood 2 to be treated at the time of shifting from the above-mentioned depressurization step to the pressurization step, so that the reduction amount is supplemented. Secondly, the space inside the tank due to the decrease of the processing liquid 20 is filled with the liquid by replenishing the processing liquid 20, and by further injecting the processing liquid 20 under pressure, the pressure vessel 1 is efficiently hydraulically pressurized. This is to apply pressure.

Then, along with the pressurization in the pressure container 1, the valve 7 is opened slightly by manual operation or intermittently operated by using a solenoid valve to open the inside of the pressure container 1 to the atmospheric pressure. Liquid in container 1 or treated wood 2
The air existing on the surface of the pressure vessel 1 is discharged to the outside of the pressure vessel 1. In this case, the processing liquid 20 is discharged to such an extent that the opening force in the pressure vessel 1 does not suddenly decrease. The discharged processing liquid 20 is introduced into the discharge tank 72 via the discharge pipe 71. The processing liquid 20 in the discharge tank 72 is a reserve tank.
Return to 19 and circulate.

After that, the operation of each device is stopped, the pressure in the pressure vessel 1 is returned to normal pressure, the lid 9 is opened, and the cart 3 is pulled out, so that the liquid-injected wood can be taken out.

When the liquid of the beech material was injected by the apparatus of this example, the injection rate of the treatment liquid was 115 to 129% by weight (average value 121
% By weight) was obtained. In the conventional method and apparatus, it is at most 70 to 80% by weight.

 5 and 6 show another embodiment.

In this embodiment, the processing liquid drawing cylinder 12 in the above embodiment is used.
In place of the valve 7 connected to the processing liquid outlet pipe 12, a pair of processing liquid conduits 13 and 14 are connected to the pair of processing liquid conduits 13 and 14.
14 are connected to the decompression device 5 with the monitor devices 170, 170 interposed therebetween.

The decompression device 5 uses the vacuum suction to process the processing liquid 20 in the pressure vessel 1.
Is a vacuum suction means for sucking the air bubbles and discharging the bubbles existing in the treatment liquid 20 or adhering to the surface of the treated wood 2 to the outside of the pressure vessel 1.

The monitor device 170 includes a filter portion 171 connected to the treatment liquid conduit 13 (14) and a monitor portion 172 integrally attached below the filter portion 171.

 FIG. 6 is a detailed view of the monitor device.

The filter part 171 is provided with a monitor wood 173 having the same or similar properties as the wood 2 to be processed, which is connected to the pipe of the treatment liquid conduit 13 (14).

The pipe of the liquid to be treated 13 (14) is connected to the upper part of the filter part 171 and attached to the side of the monitor part 172.
A decompression line is connected to 74. The filter section 171 and the monitor section 172 are separated by a base plate 175,
They are connected by a connecting pipe 177 penetrating the base plate 175. A monitor wood 173 is held on the upper end of the connecting pipe 177 by a pressing member 178.
Is fixed so as to be removable, and the upper end opening of the connecting pipe 177 is closed. Therefore, the air and the treatment liquid 20 that have entered the filter unit 171 cannot escape into the monitor unit 172 without passing through the monitor member 173.

The monitor unit 172 is provided with a monitoring window 176 at a position where the treatment liquid 20 that has passed through the monitor wood 173 is dropped, and it is possible to visually check whether or not the treatment liquid 20 has passed through the monitor wood 173.

Further, the monitor device 7 is provided with a pressure gauge 180 and a drain 182.

In the illustrated example, the monitor device is a pair, but of course, only one monitor device is required.

Then, the processing liquid 20 compressed by the pressurizing nozzle 11 of the pressure container 1 is sent into the pressure container 1, and at the same time, the depressurizing device 5 is also operated so that the processing liquid drawing pipe 12 below the pressure container 1 causes the pressure container 1 to operate. The pressure of the processing liquid 20 in 1 is lower than that in the pressure vessel 1 (about
Aspirate at 60 Torr). As a result, the air adhering to the treatment liquid 20 and the surface of the treated wood 2 is removed from the treatment liquid conduits 13, 1
Suction to the monitor device 170 side via 4.

The reason why the vacuum suction is performed at the same time as the pressurization in the pressure vessel 1 is to direct the flow of the processing liquid 20 in the pressure vessel 1 and also to perform the air discharge quickly and efficiently. That is, when the pressure in the pressure vessel 1 is increased, the processing liquid 20
Flows toward the low-pressure side monitor device 170 because it is decompressed. At this time, since the accumulated air in the treatment liquid 20 and the residual air in the treated wood 2 are lighter and have better fluidity, they gather on the monitor wood 173 prior to the treatment liquid 20,
The monitor part 17 passes through the monitor wood 173 and is connected via the connecting pipe 177.
It escapes into 2.

As the pressure injection further proceeds, the inflow of the processing liquid 20 into the monitor 172 is observed through the monitoring window 176. At this point, the treatment liquid in the treated wood 2 loaded in the container 3
It can be confirmed that 20 penetrations have been completed.

〔The invention's effect〕

According to the present invention, because of the configuration as described above, despite immersing the wood in the treatment liquid before the depressurization treatment of the tank,
A good liquid injection effect is obtained, and the number of processing steps is reduced.

Furthermore, since the liquid in the tank is opened to the atmospheric pressure through the valve to the extent that the pressure in the tank does not drop sharply, for example, the efficiency of injecting the processing liquid to the beech wood, which was 70 to 80 wt% in the conventional example, is There is also an effect that residual air existing in the liquid in the tank or on the surface of the wood to be treated can be efficiently discharged to the outside of the tank such as 115 to 129% by weight, and the treatment liquid injection rate can be further increased.

Also, since the liquid in the tank is sucked through the monitor device, the air in the liquid or the air adhering to the wood surface can be taken out, and the liquid injection status to the wood can be checked while the device is operating. The effect is that it can be visually confirmed.

[Brief description of drawings]

1 is an apparatus configuration diagram of an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of a nozzle block of a decompression device, FIG. 3 is a graph showing the performance of the nozzle block of FIG. FIG. 5 is a graph showing a vacuum pump exhaust velocity curve for calculating FIG. 3, FIG. 5 is a device configuration diagram showing another embodiment, and FIG. 6 is an enlarged sectional view of a monitor device. 1: Pressure vessel, 2: Wood to be treated 3: Container, 4,5: Pressure reducing device 6: Pressurizing device, 7: Valve 13,14: Treatment liquid conduit 20: Treatment liquid, 25: Nozzle block 170: Monitor device, 171: Filter section 172: Monitor section, 173: Monitor wood 176: Monitoring window

Continuation of the front page (56) References JP-A-54-98302 (JP, A) JP-A-53-127802 (JP, A) JP-A-62-144903 (JP, A)

Claims (3)

[Claims] 1. A method for injecting a liquid such as a resin liquid into wood in a tank whose inside can be depressurized and pressurized, comprising the following steps; a) The object to be injected on a trolley. Equipped with treated wood,
Storing the cart in the tank, and then filling the tank with the liquid; b) vacuuming the air in the tank to reduce the pressure in the tank, and the air in the tank with the treated wood; Discharging the air present inside the wood to the outside of the wood, c) after the pressure reduction is completed, the liquid is introduced into the tank by the pressure pump to pressurize the inside of the tank, and the inside of the tank is operated by the valve operation. The liquid in the tank is opened to atmospheric pressure with a valve opening that does not cause a sudden drop in pressure, and residual air existing in the liquid in the tank or on the surface of the treated wood is discharged to the outside of the tank. Injecting the liquid into the treated wood. 2. A vacuum suction line from the inside of the tank is provided separately from the vacuum suction line instead of the step of opening the liquid in the tank to the atmospheric pressure via a valve, and the same as the wood to be treated in the middle thereof. Or, a monitor device provided with monitor wood having similar properties is arranged, and the inside of the tank is sucked by vacuum suction through the monitor wood, and the residue present in the liquid in the tank or on the surface of the wood to be treated is retained. The step of injecting the liquid into the treated wood while discharging air out of the tank, and the injecting by visually observing the dripping of the liquid from the monitor wood through a monitoring window provided in the monitor device. The method for injecting a liquid into wood according to claim 1, further comprising the step of confirming the completion of the treatment. 3. A device for injecting a liquid such as a resin liquid into wood, which has the following requirements; a) a tank whose inside is depressurizable and pressurizable, and b) an object to be injected with the liquid. A trolley for loading treated wood into the tank, c) decompressing the air in the tank by vacuum suctioning the air in the tank, discharging the air in the tank to the outside of the tank, and the wood to be treated. Vacuum suction means for discharging the air present inside the wood to the outside of the wood, d) a pressure pump for introducing the liquid into the tank to pressurize the inside of the tank, e) inside the tank separately from the vacuum suction means A) a vacuum suction line for sucking the air, f) a monitor device provided in the middle of the vacuum suction line, and g) a monitor unit connected to the vacuum suction line, and a filter unit below the filter unit. Integrated And a filter unit provided with the monitor unit having the same or similar properties as the wood unit connected to the vacuum suction line. The monitor unit drops the liquid passing through the monitor unit. The position is provided with a monitoring window for visually observing whether or not the liquid has passed through the monitor wood.